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Coastal Overview for Slyne Head to Erris Head

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What is the route?
This is the primary coastal description and set of waypoints for the area between Slyne Head and Erris Head. The detailed coastal description may be used by those planning to come closer inshore or to approach one of the passage havens that are listed along the length of the route. The sequence of description is from south to north or coastal clockwise passing:

  • • Inside High Island

  • • Inside Inishbofin

  • • Inside Inishdalla and Inishturk

  • • Outside Clare Island

  • • Outside Bills Rock

  • • Outside Achill Island

  • • Outside Inishkea Island

  • • Outside Inishglora Island

  • • Outside Eagle Island
The preceding southern coast's set of waypoints and coastal description is available by clicking 'Previous', above, and vessels planning on continuing northwards, past Slyne Head and beyond, can find the following sets of waypoints and coastal descriptions by clicking 'Next'.

Why sail this route?
This is a coasting route to making it possible to easily visit the many inlets that lie along this coastal stretch of water. In thick weather, a vessel should avoid this route and head out to sea. Some dangers to navigation lie as far as six miles offshore.

What are the navigational notes?
Please use our integrated Navionics chart to appraise the route. Navionics charts feature in premier plotters from B&G, Raymarine, Magellan and are also available on tablets. Clicking the 'Expand to Fullscreen' icon opens a larger viewing area in a new tab.

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Please zoom out (-) if all of the waypoints are not displayed.
The above plots are not precise and are indicative only.


The west coast of Ireland between Slyne Head and Erris Head presents features similar deeply indented features to that of the south of it. The entire distance of 55 miles, is covered by outlying rocks and islands of which Inishshark, Inishbofin, Inishturk and Achill Island form conspicuous features. Achill Island is the largest island off the Irish coast with a remarkable north side peak that rises to an elevation in excess of 610 metres. The off lying islands provide excellent position fixing for those taking the offshore route. This runs north from Slyne Head to pass west of Black Rock, then northeast to pass to the northwest of Eagle Island.

Those taking an inshore route will find the deeply indented coast provides a host of bays and inlets with excellent shelter and magnificent scenery. Within this stretch are the beautiful havens of Clifden, Cleggan Bay, and the Killaries, along with several creeks where fishing boats and leisure craft find shelter. Although entirely exposed to the Atlantic long stretches of this coastline are fronted by islands and rocks that provide some measure of protection from the Atlantic swell and the inshore rout can save a considerable distance.

Numerous dangers, however, impede the approach to them, rendering the exercise of extreme caution necessary to ensure their safe navigation. A keen watch should be maintained as there are lobster pots on many of the rocks. Vessels operating in thick weather, between Slyne Head and Erris Head, would find it advisable to keep about two miles west of the outlying island and particularly Inishshark Island.


The complete course is 65.58 miles from the waypoint '3 miles west of Slyne Head' to '1½ miles north of Erris Head' tending in a northerly direction (reciprocal southerly).

3 miles west of Slyne Head, 53° 23.997' N, 010° 19.128' W
Slyne Head is the western extremity of the 23-metre high Illaunamid, the outermost island of a chain that extends about two miles west by southwest from the coast. A light, Fl (2) 15s, is shown from a conspicuous 24 metres high tower standing on the island. The prominent ruins of a disused light-tower stand close south of the light.

       Next waypoint: 8.88 miles, course 18.18°T (reciprocal 198.18°T)

300 metres east of High Island Breaker, 53° 32.429' N, 010° 14.467' W
Passing clear of High Island Breaker 1/2 a mile south of the east end of High Island leading into a southern approach on High Island Sound. This is a deep water channel between High Island and Friar Island. High Island lies about 2 miles west of Aughrus Point, has several old buildings on its slopes,
and rises to an elevation of 59 metres. Friar Island, 23 metres high, lies about 1/2 a mile to the east and the largest of a group of four islets. The sound is clear of dangers in the fairway although the sea can run high on both sides.

       Next waypoint: 0.79 miles, course 0.95°T (reciprocal 180.95°T)

North of High Island Sound, 53° 33.220' N, 010° 14.445' W
Northern alignment for High Island Sound.

       Next waypoint: 1.55 miles, course 34.92°T (reciprocal 214.92°T)

½ a mile northwest of Cuddoo Rock, 53° 34.488' N, 010° 12.954' W
Passing northwest of Cuddoo Rock a group of rocks some of which are always above water and others just awash.

       Next waypoint: 4.44 miles, course 61.22°T (reciprocal 241.22°T)

½ a mile southeast of Lecky Rocks, 53° 36.622' N, 010° 6.395' W
The unmarked Lecky Rocks are a group of rocks some of which are always above water and others just awash. They lie about 1½ miles east of Inishlyon Light, Fl.WR 7.5s, with the highest rock being 7 metres high and located at the northern end of the cluster.

       Next waypoint: 4.52 miles, course 21.45°T (reciprocal 201.45°T)

¼ of a mile east of Inishdalla, 53° 40.826' N, 010° 3.606' W
Inishdalla is a small 22 metres high grassy island that lies about 1.5 miles southeast of Inishturk.

       Next waypoint: 1.89 miles, course 352.15°T (reciprocal 172.15°T)

Between Inishturk and Ballybeg islands, 53° 42.698' N, 010° 4.042' W
This is in the centre of the mile wide deep water channel between Inishturk and Ballybeg islands. Inishturk has steep and rocky coasts that are bordered by cliffs which, on the west side, attain an elevation of 132 metres. The summit rises to an elevation of 187 metres and has a prominent ruined tower standing on it. The small Ballybeg Island, 17 metres high, lies inside the larger Caher Island with a fairly peaked summit, 57m high. The northwest extremity of Caher terminates in a precipitous cliff of about the same height.

       Next waypoint: 11.42 miles, course 327.81°T (reciprocal 147.81°T)

¼ of a mile west of Bills Rock, 53° 52.347' N, 010° 14.354' W
Bills Rocks is an isolated group of steep to rocks 38 metres high that are located six miles south-eastward of Achill Head.

       Next waypoint: 6.42 miles, course 339.03°T (reciprocal 159.03°T)

1 mile east of Achill Head, 53° 58.337' N, 010° 18.257' W
Achill Head is a precipitous headland rising to an elevation of 664 metres in Croaghaun, its summit about 2 miles within, the highest cliffs in the British Islands. Astounding cliffs will be seen on the northwest face under the summit.

       Next waypoint: 8.60 miles, course 8.02°T (reciprocal 188.02°T)

1¼ miles west of the Inishkea Islands, 54° 6.842' N, 010° 16.212' W
Passing outside Inishkea Islands which lie off Mullet Peninsula. The Inishkea Islands consist of two large islands which are separated by a narrow boat channel.

       Next waypoint: 10.98 miles, course 22.32°T (reciprocal 202.32°T)

2 miles west of Eagle Island, 54° 16.990' N, 010° 9.072' W
Passing outside the 58 metres high, and steep-to on its western side, Eagle Island. A light a white tower, Fl (3) 15s and 11 metres in height, stands on the western extremity of the island. Two conspicuous radio masts stand near the tower.

       Next waypoint: 6.09 miles, course 60.00°T (reciprocal 240.00°T)

1½ miles north of Erris Head, 54° 20.025' N, 010° 0.038' W
Erris Head is a 52 metres high cliffy islet fronted by rocks that extend out quarter of a mile to the north. Pigeon Islet, a conical and prominent rock, lies at the outer end of a chain of rocks which also extend up to 0.3 mile west.


The coast to the north of Slyne head as far as the entrance to Clew Bay, a distance of 25 miles, is covered by outlying rocks and islands. Vessels bound to Clifden Bay may pass Slyne Head at the distance of about ½ a mile, and steer northeast towards the conspicuous tower of Cleggan, which will be seen a little to the west of Turbot Island. A heading in this direction will lead about ½ a mile outside Clark’s Rock, and clear of all other danger. In good conditions, small vessels bound to Clifden may take the passage between Carrickrana Rocks and Turbot Island. The south side of this passage is marked by the peaked rock called Wavery Beg at its west end, and by Broad Rock at its east end. Near its middle, there are two shoals of 2.7 metres water. The best channel lying between these and the rocks extending from Turbot Island is little more than 100 metres wide and requires local knowledge for its safe navigation.

The coast to the north of Slyne Head is just as rugged as that to the south of it, with many bays and inlets. The area as far as the entrance to Clew Bay, a distance of 25 miles, is covered by outlying rocks and islands. Of these Inishshark, Inishbofin, and Inishturk form conspicuous features of the coast. Within this distance are comprised the harbours of Clifden, Cleggan Bay, and the Killaries, with several creeks where fishing boats and small craft find shelter. Numerous dangers, however, impede the approach to them, rendering the exercise of extreme caution necessary to ensure safe navigation. The soundings become very irregular as the coast is approached. In thick weather it would be prudent to keep at least five miles out from the rocks along this coast but in fine weather it is possible to stand in closer.

A rocky area, known as Barret Shoals, may be identified by rippling tides over them in heavy weather, and in gales by a heavy breaking sea. The shoalest part, 22 metres, lies 2.5 miles due north from Slyne Head lighthouse. Keeping Inishshark wholly open of High Island leads to the west of them.

Slyne Head
Photo: Irish Defence Forces

Set upon the western extremity of the island of Illaunamid is Slyne Head. The island is the western most of a chain of rocks and islands that extend two miles west by southwest from the nearest part of the mainland. The north side of the head is steep-to, with 30 metres 200 metres out from it. To the west, foul ground extends out for a ¼ of a mile, succeeded immediately by deep water. Two circular white lighthouses stand on Illaunamid, the largest of the Slyne Head islands. The conspicuous black 24-metres high active Slyne Head Lighthouse stands on the higher ground with the prominent ruins of the former lighthouse standing close south.

Slyne Head – lighthouse Fl (2) 15s 35m 19M position: 53° 23.997'N, 010° 14.051'W

There are several boat passages between the islands. Joyce’s Sound, the one most frequently used, near the inner end of the chain. The pass is only 45 metres wide and the sea frequently breaks across it. But in settled weather and smooth water, these passages may be taken in safety by those familiar with them.

The most outlying dangers that cover the shore between Slyne Head and Clifden Bay are Clark’s Rock, the Carricknaguroge, and Carrigeenboy Rocks, Pollticaur and Young John’s rock, with the Tannymore Breakers and Shoals extending from Knock Point.

The pinnacle Clark Rock uncovers to 0.6 metres at low water and lies 1½ miles northeast from Slyne Head. It has plenty of water outside it with depths exceeding 5o metres, 300 metres to the west. It is about a mile from the nearest shore, and a ¼ of a mile to the northwest of the Carrickarone Rocks, which are 6 metres above high water, and serve to mark its position when it does not break.

A mile to the east of Clark Rock, and ½ a mile west by north from Inishkeeragh the nearest shore, is Carricknaguroge, or Red Rock, that covers on spring tides. Carrigeenboy, or Yellow Hound Rocks, lying a mile to the northeast of Red Rock and ¾ of a mile from the shore, is generally visible and steep-to.

With 8.2 metres water Tannymore Breaker, lies ¾ of a mile to the northeast of Carrigeenboy and one mile and ¾ northwest from Knock Point. At ½ a mile within it Pollticaur or Spray Rock dries to 1.8 metres at low water. The whole area between it and Knock Point is occupied by rocky and foul ground over which the sea almost always breaks.

By day, on rounding Slyne Head, Cleggan Point lighthouse will be seen to the west of Turbot Island, bearing northeast, and keeping it upon that bearing will lead to the west of all these dangers.

Cleggan Point – lighthouse Fl (3) WRG 5s 17m W16M position: 53° 34.492’N, 010° 07.735’W

Knock Point, the west point of the entrance to Mannin Bay Click to view haven, is distinguished by an isolated conical hill, 38 metres high, and forms a conspicuous feature of this low reefy shore. Dangerous reefs, on which the sea breaks heavily in bad weather, extend from Knock Point in a northerly direction; beyond which, at the distance of 1.75 miles from the point, is Mweem More, or Big Breaker Shoal, with 6.4 metres water over it.

There is a narrow but deep passage between Mweem More and the Knock Point Shoals. The leading mark for this is Clifden Castle, touching the north side of Illaunrush, on the alignment 069°T of Clifden Castle, passes between Mween More’s southern side and north of Young John’s Rock plus the Testy Breakers.
Please note

The big, ruined, grey Clifden Castle is not always easily distinguished from a distance.

Local fishermen work their way among all these dangers, but the safest approach to Mannin or Clifden Bays is to the north of Mweem More, and between it and the Seal Rocks. The leading marks for this is the alignment 080°T of a white beacon on Fishing Point, on the southwest side of the entrance to Clifden Bay, and Clifden Castle.

The approaching alignment of 080°T of a white beacon on Fishing Point and
Clifden Castle

Image: Graham Rabbits

This leads east towards the entrance to Clifden Bay between the conspicuous Carrickrana Rocks and Mweem More, then to the south of Coghan's Rocks and north of Doolick Rock, as best seen on Admiralty Chart 2708. For those approaching Mannin Bay, follow this leading mark until the alignment of 315°T of Waverymore, 600 metres north by northwest, of the summit of Cruagh Island, 3 miles northwest, and then follow this alignment into Mannin Bay.


Clifden Castle, Clifden Boat Club and the tidal inlet leading up to Clifden
Image: Tourism Ireland

Clifden Bay is entered between Errislannan Point and Fahy Point to the north. The bay is separated from Mannin Bay by a peninsula which, blends in with the high land to the north, making the entrance difficult to distinguish. Within the bay Clifden Boat Club Click to view haven, located at the eastern end of Clifden Bay, provides a well-sheltered anchorage and visitor moorings with an all tide jetty and a slip for the convenience of landing.

Clifden Quay
Image: Tourism Ireland

Clifden Click to view haven has a tidal quay, approachable HW ± 2 hours, that is situated 5 minutes walk from the heart of the town. It is suitable for boats that can take-to-the-bottom and usually has space available. The town's wide variety of interesting shops and supermarkets make it the best point to stock up in this part of the coast. A jetty in the river below the supermarket, accessible by dinghy near high water, further facilitates this. This together with lots of bars and restaurants within the town all help to make Clifden a really worthwhile destination.

Lying to the north of Clifden Bay, are two shallow inlets, Streamstown and Kingstown Bays, approached by intricate channels between the numerous dangers that cover the coast. The former inlet indents the land to a distance of 3.5 miles and may be navigated by leisure vessels to its head at high water, where it expands into a shallow pool.

The largest and outermost island, lying two miles west of Aughrus Point, is High Island. It rises to 59 metres and its sides are precipitous making landing generally difficult. The ruins of several ancient ecclesiastical buildings are found on it, consisting of a church or abbey of the 7th century. 400 metres of its north eastern side are a scattered group of steep-to rocks called Cowrakee, or Odd Rocks, that uncover at 2 hours ebb. Its outer extremity is clear of outlying dangers.

Lying between High Island and Carrickrana Rocks is Cruagh Island. It rises in a peak to a height of 58 metres and has foul ground extending ½ a mile to the west of it. A mile to the south of Cruagh Island lies Mweem Cruagh, or Cruagh Breaker, a dangerous shoal with 3.7 metres of water over it.

To the east of High Island lies Friar Island and a deep, clear, 800 metres wide channel runs between them called High Island Sound. On the eastern side of Friar Island is Friar Island Sound. This is a narrow passage, with a least depth of 9.4 metres at its southern end, that passes between Friar Island and Mweelauntrogh, a group of drying rocks to the east.
Please note

The currents set very strongly through this channel and it is turbulent with the wind against the stream.

Two miles to the northeast of High Island is Cuddoo Rock, elevated 6 metres above high water. 1½ miles further east is Roeillaun. This rocky point, foul to some distance, forms the west point of the entrance to Cleggan Bay Click to view haven.

Within this outer line of dangers, there are numerous rocks and islets which it is unnecessary to give a particular description of, as only local sailors should come within a mile of the outlying islands of Cruagh and High Island. In fine settled weather, with smooth waters, coastal cruising leisure vessels may save a great distance over High Island Sound by taking the inshore route through the Aughrus Passage. The Aughrus Passage lies between Aughrus Point and Carrickculloo; situated 800 metres to the west of the point. The navigational width is just 200 metres, in 7.8 metres water, between foul ground on each side where tidal streams are reported to be strong.
Please note

The Aughrus Passage requires local knowledge for its safe navigation, as any positioning mistake or confusion of leading marks might prove fatal.

Those Leaving Clifden Bay by this route should steer either to the north, or south, of the Carrickrana Rocks; then with the stern mark of Knock Hill in line with the outer side of the Carrickrana Rocks, steer between Eeshal Island and Cruagh Breaker. After passing these take care to avoid Glinsk Rock, that covers at half tide, by keeping Waverymore open of Eeshal Island. Continue between Gowla Rock and Carrickaun; passing to the east of the 1.4 high Gowla Rock and west side of the 2.2 metres high Carrickaun.

From here adopt the alignment of 338° T of the west side of Carrickaphuill, situated 1,500 metres to the north by northwest, and the west side of Inishbofin, situated 5 miles north by northwest, that provide the leading mark through the channel. Once through, and when the whole of High Island comes open north of Carrickculloo, prepare to haul up for the east end of Cuddoo Rock by picking up on the alignment 203° T of the summit of Carrickculloo and the west side of Cruagh Island, situated 1½ miles to the south by southwest. Steer northeast along this leading mark between Cuddoo Rock and the Ferroonagh West and East Rocks, and clear of all the dangers on the Aughrus shore.

The final alignment for those who want to pass close to the mainland is the 236° T of the north side of Friar Island and the southeast side of High Island that leads northeastward passing to the northwest of Dog Rock and across the mouth of Cleggan Bay to join the main inshore route. All the leading marks are best seen on Admiralty 2707.

Foul ground extends from Roeillaun, the west point of the entrance, for a ¼ of a mile to the north, on the outer edge of which are the Carrickamwelaun and Dog Rocks, uncovered at low water.

Cleggan Point is bold too with the single danger being a rock lying less than 100 metres from a small detached islet under the head. The whole eastern shore of the bay may be approached to 100 metres.


Ballynakill Harbour
Image: Tourism Ireland

Ballynakill Harbour is an open inlet that opens at the head of a bight formed by Cleggan and Rinvyle Points and reaches deep inland to include a number of islands and several small bays. About 2 miles within the entrance there are many suitable places to drop anchor with good protection in moderate depths.

Tully Mountain rising from the sea at the entrance to Ballynakill Harbour
Image: Tourism Ireland

Ballynakill Harbour Click to view haven offers an easy quick-access passage anchorage, particularly so with the prevailing westerly wind, under the 26-metre high island of Freaghillaun South situated in the mouth of the harbour.

The anchoring area behind Freaghillaun South
Image: James Stringer via CC BY-SA 2.0

Further in there are several anchoring opportunities with outstanding mountainous views most notably Fahy Bay Click to view haven a well-protected bay entered over a sand bar 2½ miles within the entrance. Currents in Ballynakill Harbour are generally weak and the shelter good so it is a great location for some exploring.
Please note

Keep clear of the fish farms located in this area.

At anchor in tranquil Fahy Bay

The south shore of the approach, from Cleggan Point to the east, is bold and steep-to; sloping abruptly in bold rocky downward slopes, or breaking at an altitude of 60 metres into cliffy coves. The north shore is not so bold and has several rocks scattered along it. The 18 metre high Inishbroom forms the north point of the approach and it is connected to Rinvyle Point by a shallow ridge of gravel and rocks. A central approach between the two points presents no danger and Tully Mountian, rising to 356 metres on the north shore of the entrance, provides an excellent sea mark for its approach.

A short distance from its northern point there is a detached rock called Puffin Rock, that is always visible, and a ¼ of a mile to the west of Inishbroom is another rock, named Mweelaunatrua, that shows at 4 hours ebb. New Anchor Rock lies 300 metres southwest of Inishbroom, and is steep-to. The alignment of 006°T of the eastern extremity of Inishdalla, four miles to the north of Mweelaunatrua and a ruined tower set upon the west end of Clare Island, seven miles further north, passes to the west of Mweelaunatrua and the foul ground west of Rinvyle Point.

Several rocks lie off the point south of Inishbroom. The outer of these, called Tooreenadurane, is a ¼ of a mile out from the shore and uncovers at 4 hours ebb. From there to the 11-metre high Braadillaun Rock the shore is then bold. A vessel will stay outside of these by keeping on a line of bearing of 325° T of the southwest extremity of Inishbroom open to the southwest of Braadillaun. The same leading line serves to passes to the southwest of Ship Rock that is situated further within Ballynakill Harbour.

The Islands of Inishshark, Inishbofin, and Davillaun, with their adjacent rocks, lying 1½ miles to 2½ miles off this part of the coast. They extend about seven miles in an east and west direction and afford some measure of shelter to Cleggan Bay and Ballynakill Harbour. The northern shores of the islands are bold-to and free from danger, with 55 metres of water ½ mile off. In the sound, between them and the main, there are some outlying dangers to be avoided; but the fairway channel is deep and clear.

The westernmost of the group, Inishshark, is about 1½ miles long and 94 metres high. It has rugged, precipitous shores, that reach an elevation of 75 metres on the western side. The coast of which is deeply indented with fissures called "ooghys," and is surrounded by outlying rocks and islets. A very remarkable rock called Boughil, or ‘the boy’, rears itself to the height of 69 metres, at about 200 metres from the cliffs on its northwest side, and has 27 metres of water close to it. A conical rock, 9.9 metres high, called Colleen, or ‘the girl’ lies about the same distance on the west side of the north point. Several other rocks lie scattered along this precipitous shore.

Extending more than ½ a mile north-west from Shark Head lie the Kimmeen Rocks. They are principally above water, but have several dangerous rocky patches, or breakers, extending to the southeast, which makes it necessary to avoid cutting in too close when approaching Shark Head. The southernmost of these is of less a concern to leisure craft, with 2.7 metres of water over it, and lies a ⅓ of a mile southwest from Shark Head. The north Stag of Bofin, a rocky extension from the northeastern point of Inishbofin, seen open of Colleen Rock, presents a leading line that keeps vessels outside to the north of the Kimmeen dangers and Inishbofin’s south point shut in with the north point of Inishgort leads to the south of them.

A rocky shoal called Mweemore, with 7.3 metres water over it, lies 1¼ miles south from Shark Head and a mile from Inishgort. Within it are several other rocky heads, on all of which the sea breaks when the swell is high. A lead line of bearing is 085°T of the summit of the 353 metres high Tully Mountain located 4.5 miles east of Cleggan Point and open north Cleggan Point, passes south of these breakers and north of the dangers on the west side of the entrance to Cleggan Bay. As best seen on Admiralty 1820.

The small island of Inishgort with several scattered rocks around its west and south sides lies a ⅓ of a mile south of the southeast point of Inishshark. The passage between these two islands has several dangers and is fit only for small local boats. The Tide Rock, within Ship Sound, seen just open to the west of Inishbofin on a line of bearing of 347°T, will lead clear of the easternmost rock off Inishgort. By night Slyne Head lights kept in sight to the east of High Island clears Inishgort Rocks.

The strait between Inishshark and Inishbofin is called Ship Sound. It is about ½ a mile wide and is obstructed by a chain of rocks and islands on the Inishbofin side. Between this and Inishshark there is a channel where, in settled conditions with smooth water and a leading wind or under power, a leisure vessel may take this channel. To the west of Inishshark and never covered the Tide Rock marks the channel well. The best water lies about 60 metres to the west of it. However Ship Sound tides are strong, attaining 2.5 knots at springs, and the stream continues to run through the sound for 2 or 3 hours after high and low water by the shore, the flood coming from the south.
Please note

When the swell is up it breaks right across the sound rendering it impassable.

Inishbofin as seen from the northwest
Image: Jack Kelly External link

Inishbofin is the largest of this group and it has an irregular outline; rising in three principal eminences, the highest of which, near the west end, is 84 metres above the sea. It lies with its west end about ½ a mile east of Inishshark Island. Including Inishlyon, which is joined to it by a ledge of rocks uncovered at low water, it is about four miles long from east to west and almost two miles across at the widest part. There is a light shown from a structure standing at the east extremity of Inishlyon.

Inishlyon - lighthouse Fl WR 7.5s 7/4M position: 53° 36. 731’N, 010° 09.584’W

Bofin Harbour as seen from the east
Image: Jack Kelly External link

There are two harbours Bofin Harbour Click to view haven, to the South and Rusheen Bay on the East side of the Island where anchorage can be taken by leisure vessels, in 5.5 metres near the head.

Both range marks on the north shore with the towers in transit

The position of Bofin Harbour may be readily identified from seaward by a high round white beacon tower that stands on Gun Rock that is situated on the east side of the entrance. The tower stands 12 metres high (6.7-metre above high water) and has a lit beacon, white column on a white hut Fl(2)6s8m4M, standing close by.

Ferry entering passing the beacon tower on Gun Rock
Image: Jack Kelly

The entrance to Bofin Harbour is marked by two range marks.

  • • The harbour's modern Port Entry Light 021° T. It shows a narrow white sector centred on 021°T with 5° sectors either side, Red to the west, Green to the east. As illustrated, the leading light is usually bright enough to be seen in daylight. Simply follow the white lead into the harbour on a bearing of 021° T.

  • • The historical alignment of two white towers on the northeastern side of the harbour. These lie close east of the Port Entry Light and safely lead in when inline at 032° T. However, this range passes somewhat unnecessarily close to the east of a covered rocky area lying about 150 metres southwestward from the beacon on Gun Rock which has 1.2 metres of water LAT over it - see haven entry.

On the north side of Rusheen Bay are the Black Rocks, always above water, with other tidal rocks around. Do not approach their south side within 100 metres, and give their east by north-eastern side a wide berth, to avoid Coramore Breaker, with 4.2 metres of water, that lies just over 200 metres from the rocks in this direction.

¾ of a mile long and 300 metres wide, with an elevation of 24 metres, Davillaun lies off the east end of Inishbofin. It is located ¾ of a mile to the east of the Black Rocks, with a deep and clear channel between them. Its west end is foul to 300 metres. Off its east end lies Couraghy Rock, dry at low water, and 800 metres to the east beyond it is the Davillaun East Breaker with 2.1 metres over it. Keeping Cleggan Point to the east of Lecky Rocks clears the Davillaun East Breaker.

The most dangerous rock in the sound between Inishbofin and the mainland is Carrickmahoy. It is uncovered at 4 hours ebb, lies ¾ of a mile south of Inishlyon light, and a ⅓ of the distance across the sound towards the entrance of Cleggan Bay. Foul ground extends for 200 metres to the east and west of it, and it is connected with Inishlyon by a bank with 7.3 to 16.5 metres over it, and with 24 and 26 metres on each side of it. The sound between Inishbofin and Inishshark seen at all open leads to the south of it. The west ends of Inishturk and Davillaun Islands in line leads to the east of it, and the west end of Inishturk over Lyon Head leads west of it. The highest part of Inishshark over the south side of Inishbofin leads over the bank to the north of it, in 11 metres water.

An extensive cluster of rocks, Lecky Rocks always above water, lie ½ a mile south of the east of Inishlyon light. They form 2 distinct patches, with a channel of from 6.5 to 10 metres water between them, and together occupy a space of ½ a mile in length in an east and west direction, and a ¼ of a mile in width. The highest part, situated on the northern patch, is 7.5 metres above high water. Rocky outliers extend 300 metres both to the north-west and south-east of the southern rock. They are otherwise moderately bold-to. The channel between them and Inishbroom is 1½ miles wide, with a depth of 26 metres water, and is the narrowest part of the strait that separates this group of islands from the main.


Mighty Mweelrea and the outliers as seen from Inishbofin at dawn
Image: James Stringer via CC BY-SA 2.0

The coast to the northeast of Rinvyle Point and Inishbroom is encumbered with outlying rocks and dangers. These obstruct the approach to the important inlet of Killary Bay although a good passage does reside between them.
Please note

Approach it with caution, particularly at night or in bad weather.

The 8 metres high Live Island, or Illaunamina, that resides a mile to the northeast from Inishbroom, is moderately bold-to to the north. To the south of it are detached rocks that extend for nearly 400 metres. On a shallow bank that extends from it to the shore there are 2 small rocks, called the Puffin Rocks, that dry at low water.

The long Fjord like Killary Harbour
Image: Tourism Ireland

From a position north of O'Mally Breaker the entrance to Killary Harbour Click to view haven bears southeast by east, 3.75 miles. Set deep in a narrow inlet between high rugged precipices that descend steeply to the shore, it has been likened to a miniature Norwegian fjord.

Killary Harbour alignment marks, Doonee Islet with Inishbarna Islet rear

Beacons on Doonee Islet and Inishbarna, situated off the peninsula of Rossroe that separates Killary Harbour from Little Killary Bay to the south, provide a range mark. Aligned on 099°T they lead in between O'Mally Breaker and Carrickgaddy Rocks and then, south of Inishdegil More and northward of Thanymore shoal that has 8.8 metres over it.

Yacht anchored in Killary Harbour
Image: Tourism Ireland

The smaller Little Killary Bay (Salrock) Click to view haven resides directly to the southeast.

The coast to the north of Killary Bay, called the Murrisk shore, runs about northeast by north for 8 miles to Roonah Head that marks the southern entrance point of Clew Bay. Its general character is sandy, broken at intervals by low rocky points, from which dangers extend to seaward for upwards of a mile. The surf is almost incessant on these beaches which makes a landing very difficult.

At about the midway point of this shore is Devlin Point where a conspicuous hill of the same name will be seen to rise to the height of 269 metres. Between it and Roonah Head the land near the shore declines in height, nowhere exceeding 42 metres.

Together occupy a space a mile in length Govern and Frehill Islands lie in a north by northwest and south by southeast direction. The 10.5 metres high Govern Island, at the south end of the group, lies above ¾ of a mile west by northwest from Dooaghtry Point and one mile east by northeast from Gaddymore. Frehill, a grassy island near the north end of the group, is 20 metres high. They are surrounded by outlying dangers, particularly on the western side; but there is a passage between them and the rocks that border the shore.

Uncovered at low water, Blood Slate Rocks lie nearly a mile northwest by west from Frehill Island. ½ a mile southwest by west from the island, there is another rock, awash at low water. The summit of Inishbarna, seen over the north point of Inishdegil More, leads to the west of both these rocks. Cleggan Point shut in by the east side of Live Island, 224°T as seen in Admiralty chart 2706, leads to the north of the Blood Slate Rocks.

Dry on last quarter ebb Carrickamurder Rocks lie on the outer part of a shoal extending ¾ of a mile northwest of Barnabaun Point. Tully Mountain, over the north end of Frehill Island, leads outside them.

Off Cross Point are Carrickmalagh and Road Rocks the next to the north of Devlin Point, at the distance of a mile from the shore. The former is only covered at high water springs, the latter, lying 1,100 metres to the northeast of Carrickmalagh, only shows at low water springs. A bearing of northeast-by-east of Roonah Head bearing leads outside both these rocks.
Please note

This is a very dangerous part of the coast and when the swell is high it breaks far beyond the dangers described. Leisure vessels should strive to give the area a wide berth.

Two miles north-east of Cross Point is Emlagh Point. It is backed by 12 to 15 metres high sandhills and based on a rocky foreshore that uncovers out to a ¼ of a mile. Between Road Rock and Emlagh Point, the bottom is clean sand with regular depths, affording an anchorage with offshore winds. This is particularly useful when the wind is blowing so strong from the east that vessels cannot beat up Clew Bay.

At Roonah Head the coast turns sharply to the east, forming the southern shore of Clew Bay. Foul ground extends for more than a mile to the west of the head, and beyond this lies the very dangerous Meemore Rock, together obstructing nearly ½ the sound between Roonah Head and Clare Island.

Inishturk and Inishdalla as seen from Inishbofin
Image: Andreas F. Borchert via CC BY-SA 2.0

Lying nearly midway between Inishbofin and Clare Islands and 6 miles from the mainland is Inishturk. The summit rises to an elevation of 187 metres and has a prominent ruined tower standing on it. The steep and rocky coasts are bordered by cliffs that attain an elevation of about 132 metres on the west side. An anchorage can be taken off InishturkClick to view haven in a bay on the east side of the island, protected from west winds. The best berth lies about midway between the entrance points where leisure vessels may anchor as close in as possible in good holding. On the southeast side of Inishturk there is a small bay that affords very good shelter with the wind from north round through west by southwest. Anchor midway between the points of the bay in good ground, lying as close to the shore as possible. A stream falls into the little cove, making it very picturesque.

Nearly a mile to the south by southeast from its west end lies the Roger Chase Shoal, with 12.8 and 14.6 metres of water over it and 35 metres around. ½ a mile from its southeast point are the Floor Shoals with from 5.5 to 7.3 metres of water. The sea breaks on all these in bad weather. Roonah Head open to the south of Caher Island leads to the south of them all. The east point of Inishturk bearing north leads to the east of Floor Shoals.

Inishdalla a grassy islet, 800 metres long and 400 metres wide, lies a mile to the southeast of Inishturk, and is clear of danger excepting on its southwest side. Here foul ground extend out a ¼ of a mile, with rocks on it that uncover at half tide. On the north side of its eastern point is a small inlet, with a sandy beach, where boats may land in moderate weather.

Caher Island, lying 1½ miles to the east of Inishturk, is ¾ of a mile in length and a ⅓ of a mile wide, with a 57 metres high summit. Its northern extremity terminates in a bold cliff of about the same height. A few detached rocks lie around its southern side, but the northern half of the island is steep-to. The best landing is on the southeast side, at Caher Point, where there is scarcely any rocky margin; and a little further north there is a small sandy cove called Portatemple.

On the west side of Caher lies the small 17 metres high islet of Ballybeg. It is about a ⅓ of a mile long and has foul ground extending 200 metres to the east of it. Between it and Caher there is a clear channel with 14.6 metres water; and between it and Inishturk, there is a depth of 37 metres over a sandy bottom.

During extended westerly gales the space between these islands and the mainland is covered with breakers. The first shoal met with in coming from the west is the Pollock, with 7.7 metres water. An extensive tract of shoal water, with from 7.3 to 11 metres water over it, called the Middle Ground, next presents itself, occupying the greater part of the space between Caher and Frehill Islands; all of which breaks in bad weather, and is very dangerous area at such times.


Clew Bay seen from Croagh Patrick Mountain
Image: Mal B via CC BY-SA 2.0

Clew Bay, a spacious inlet, with moderate depths of water and ease of access, is remarkable for the number of small islets that occupy its eastern portion; within some of these there are well-sheltered anchorages for vessels of shallow draught; and between them are intricate channels leading to the commercial towns of Westport and Newport.
Please note

This part of the coast is remote, rocky and wild. There can be a confused sea between Clare Island and Achillbeg but especially off Achill Head itself.

Inishgort Lighthouse and its remote islands and intricate channels behind
Image: Tourism Ireland

The approach to the bay is well marked by Clare Island lying in the middle of the entrance, with Achill Island on its north side and the 756 metres high Croagh Patrick Mountain in the distance on the south shore. The principal entrance, between Achillbeg and Clare Island, is a 1½ miles wide, has 40 metres water and is free from hidden danger. The southern entrance between Clare Island and Roonah Point has not more than 12.8 or 14.6 metres water and is encumbered with several dangerous shoals.

Croagh Patrick Mountain
Image: Tourism Ireland

Clare Island, the most imposing feature in the approach to Clew Bay, stands boldly out in the middle of the entrance and serves both as a distinguishing mark and a valuable breakwater against the heavy Atlantic swell. Its northwest face is composed of immense cliffs, rising from the sea to the summit of the island, at an elevation of 459 metres within 400 metres of the water's edge. Viewed from this quarter it presents the appearance of a tabular mountain, dipping slightly to the southwest, where it terminates in a bluff point with the ruins of a tower standing on it. To the northeast, it descends, in a rugged, comb-like appearance, to the disused lighthouse on the northern point of the island. Detached masses of rock are scattered along the shore to the distance of 400 metres from the cliffs, with deep water in close to them. The south shore is of more moderate elevation and is generally foul out to 400 metres off. From about the middle of this shore, a deep valley runs across to the east side of the island, the land to the south of it again rising to the height of 215 metres.

Clare Island seen from Croagh Patrick Mountain
Image: Tourism Ireland

A circular white unlit lighthouse stands on the north point of the island at an elevation of 102 metres above the sea. The structure is visible in clear weather from 20 to 30 miles and serves as an excellent guide to the north entrance of Clew Bay. It also marks the position of Calliaghcrom Rock or Deace’s Rock. This small rock, which is never covered, lies about ½ a mile north of the northern extremity of the island, and must be carefully avoided at night or in thick weather. Its situation is generally revealed by the breakers.

Clare Island – lighthouse Fl R 3s position: 53° 48. 020’N, 009° 57.060’W

Clare Island Lighthouse
Image: Tourism Ireland

½ a mile north by northwest of the northwest extremity of the island is Two-Fathom Rock. The rock has 3.4 metres of cover but the sea breaks heavily upon it in bad weather making it dangerous. It is steep-to all round, with 27 and 31 metres water between it and the island. Foul ground sldo extends for a ⅓ of a mile to the southeast of Kinnacorra Point, the east point of the island.

Clare Island Harbour overlooked by Grainne Mhaol's Castle
Image: Tourism Ireland

The principal landing place for Clare Island Click to view haven at the island’s pier that is set into a small sandy bay, by a lighthouse, at the southeast end of the island.

The foreshore uncovers to some distance outside at low water and at high water it is subject to a great deal of run. Standing prominently on the south point of this bay is an old castle, once the residence of the famous pirate queen Grainne (Grace) O'Malley, also called Granneuaile or Grania Wael. In fine weather small vessels may anchor in this little bay at about 300 metres from the shore, in 5.5 metres water; but it is exposed to southerly winds, and the holding ground is bad. Near the north point of the bay there is a rocky cove where a landing can generally be made. Vessels seeking a more sheltered anchorage should head into Clew Bay where you will find complete protection at Westport Click to view haven

Lying near the middle of the south entrance is the 19 metres high rocky islet Mweelaun. It is steep-to all round, apart from a rocky patch on its south side extending about 200 metres from the rock. Vessels bound to Clew Bay from the south generally pass between Mweelaun and Clare Island, to avoid the dangers that lie off Roonah Head.

The most outlying danger off Roonah Head, Meemore, is only uncovered at low water springs. It lies nearly in a direct line between Mweelaun and the north face of Roonah Head, on an east-by-southeast and west-by-northwest line of bearing, nearly two miles distant from the former and 1½ miles from the latter. When the situation of this rock can be clearly made out, as it frequently may be by its breaker, a vessel may safely pass between it and Mweelaun.
Please note

Care must be taken not to mistake it for the Black Rock that resides ½ way between Meemore and the mainland.

Only covered on last quarter flood, Black Rock lies nearly a mile from Roonah Head. It is 0.65 of a mile from the nearest part of the shore and the whole space between the Black Rock and the shore is occupied by rocks and foul ground. Black Rock and can generally be made out by its breaker. Meemore, however, is frequently concealed. There is 11 and 12.8 metres of water in the channel between them, but both rocks are foul to a ¼ of a mile off. Passing to the north of Mweelaun will lead well clear of Meemore.
Please note

It is at all times dangerous to pass between Meemore and the Black Rock.

The south shore of Clew Bay, from Roonah Head to the east, is diversified by the clay cliffs in front of the 170 metres high Carrowmore Hill, the fine sandy beach off Louisburgh and the picturesque hills of 144 metres high Oldhead. The fine range of Croagh Patrick, commonly called the Reek, rising to the height of 749 metres, and forming one of its most remarkable features.

The 104 metres high, and bold-to on its southwest side, Achillbeg, or Little Achill, forms the north point of the north entrance to Clew Bay; the southern point being the lighthouse point on Clare Island, two miles away. When viewed from the east or west, at the distance of three or four miles, it presents the appearance of two high hills, the middle of the island being very low and nearly overflowed by the wash of the sea. It is separated from the main by a narrow channel called Blind Sound that is navigable at high water except when there is a heavy sea running.

To the east of Achillbeg the south entrance to Achill Sound opens. Here, off a small sandy bay, leisure vessels may anchor in good weather, but in southwest gales the sea breaks right across the entrance.

Achill Sound, which separates Achill Island from the mainland, is entered close north of Achillbeg Island. The ruins of a fort, with a drying quay west of it, stands on Darby Point, the west entrance point of the sound. The sound extends north for about eight miles to the north entrance. It is spanned by a swing bridge about halfway along its length, and dries for a distance of a mile south of the bridge. When open there is a passage on each side of the bridge 13.7 metres wide. The east passage has a depth of 2 metres at HW whereas the west side is rocky and dries out.
Please note

The bridge can only be opened during working hours 0800-1600 Monday – Thursday and 0800-1500 Friday. Mayo County Council, +353 098 41169, require at least 24 hours notice for the bridge to be opened.

Inishgort Lighthouse leads into the channels between the islands of Clew Bay
Image: Peter Craven

Vessels entering Clew Bay from the south after rounding Inishshark, steer northeast for the summit of Clare Island, which will be seen open to the west of Inishturk. Pass between it and Mweelaun Islet, from where the course to Inishgort lighthouse is east by south 12 miles.

Inishgort - Lighthouse Fl 10s 10M position: 53° 49. 603’N, 009° 40.264’W

Rosmoney Jetty
Image: Peter Craven

Once within Inishgort the complex drumlin coastline and its countless anchorages are perfectly explored by boat. The central Rosmoney Click to view haven, or Collan More Harbour to the east of Collan More island, and not far within the entrance, provides all-round shelter, direct access to the mainland and a convenient place from which to explore the archipelago. It is also home to the Mayo Sailing Club and Glenans Sailing School. It offers an anchorage, club moorings, a pier and a club jetty for the convenience of landing.

The view northwest from Ashleam Point over Ashleam Bay
Image: Tourism Ireland

From the north, after rounding Achill Head, vessels may proceed as close as the wind and swell will permit, shaping a course for Clare Island lighthouse, taking care not to go to the north of this course, on account of a bank of 11 metres lying a 1½ miles to the west of Dooega Head. This is not dangerous with smooth water but dangerous heavy breakers develop when the swell is up. Another reason for not hugging this shore, particularly with light winds, is that both streams press down on it. Besides this, there is no danger near the fair way until Calliaghcrom, or Deace’s Rock. As the unlit lighthouse on Clare Island is approached from abreast, a southeast by east course for 11 miles will then carry a vessel to Inishgort lighthouse.

The coast of Achill Island to the northwest of Achillbeg presents a bold rocky shore, backed by rugged mountains. Ashleam Point, lying three miles to the northwest of Achillbeg, has a dangerous reef that uncovers at half ebb and extends ½ a mile out from it. Two miles further in the same direction is Dooega Head, faced by precipices on its western side of 240 metres elevation. At the distance of 1½ miles from the head, in the direction of the Bills Rocks, there is a rocky shoal, with 11 metres water, that breaks heavily in bad weather.

A small group of 38 metres high rocks called Bills Rocks reside 6.5 miles to the southeast from Achill Head, and 8.3 miles to the northwest from Clare Island. They are steep-to and clear of danger all round. They can be readily seen clearly during the day but are unlit and therefore dangerous at night.

Keel Bay
Image: Tourism Ireland

To the west of the head, Keel Bay presents a long sandy beach, with the small Inishgalloon island at its west end, where a small vessel may find temporary anchorage in very fine weather at Achill Island Click to view haven. The head of the bay is shallow, with foul ground extending out ½ a mile from it

Keem Bay, Achill
Image: Tourism Ireland

There is another fine weather anchorage at the stunning location of Keem Bay. However, the whole coast is so much exposed to the heavy Atlantic swell that any near approach should be made with extreme caution.

Keem Bay, Achill
Image: Tourism Ireland

Three miles to the south of Achill Head and always above water are the steep-to Dysaghy Rocks. They are the outermost of several detached rocks that extend from the shore. They are about ¾ of a mile from Moyteoge Head and about a mile from the nearest shore.

Achill Island as seen from the north
Image: Tourism Ireland


The bold precipitous headland of Achill Head resides between Clew and Blacksod Bays. It rises to the height of 664 metres at its summit, called Croaghaun Mountain, from which the cliffs descend sheer down to the water's edge. The extreme point of the head runs out in a narrow ridge for two miles to the west of the summit and is surrounded by precipices of from 108 to 270 metres elevation. The detached rock, 27 metres high Carrickakin islet, lies ½ a mile to the west of the head with the passage between them obstructed by sunken rocks with 2.9 metres over them. The head is otherwise clear of hidden danger, with 55 metres water close to it, but the seas can be rough here in heavy weather and are almost always lumpy.

Twelve miles to the northeast of Achill Head lies Blacksod Bay Click to view haven, one of the finest bays on the west coast of Ireland. Blacksod Bay is protected on its west side by the Mullet Peninsula, has easy access, and affords a secure anchorage.

Blacksod Pier situated in the Southern end of the Mullet Peninsula
Image: Tourism Ireland

The entrance is between Duvillaun More and Saddle Head, the north point of Achill Island. It is about 3 miles wide, with a depth of up to 48 metres water. It is easily recognized by day by the bold promontory of Achill, and by night by the Blacksod Lighthouse standing on the north side of the approach at the southern end of the Mullet Peninsula.

Blacksod Lighthouse
Image: Tourism Ireland

A heavy swell rolls in through the entrance in westerly winds and in bad weather it breaks on a bank with 14.6 metres of cover that lies about a mile to the south of Duvillaun More.
Please note

With southerly winds the entrance is subject to heavy squalls from the high mountains of Achill and they can be so violent that a precautionary deep reef is advisable.

Black Rock
Image: MikaLaureque via CC ASA 4.0
The largest of a cluster of rocks lying on the north side of the entrance to Blacksod Bay is the Black Rock. Situated 6½ miles from Achill Head and 4½ miles to the west of Duvillaun More, the 82 metres high island is surmounted by a circular lighthouse.

Black Rock – lighthouse Fl WR 12s 22/16M position: 54° 04. 061’N, 010° 19.222’W

This serves as an excellent guide to Blacksod Bay, and for clearing the dangers in its vicinity. The light shows white to seaward, and red towards the land between the bearings southwest by west and northwest by west. By not opening the red light a vessel will clear the outlying rocks and islands that cover the shore to the northeast of the Black Rock. The southern edge of the red sector leads into the entrance of the bay, clear of the uneven ground south of Duvillaun More. Detached rocks extend for a mile and a ¼ to the west of the Black Rock, which a vessel entering the bay at night must be careful to avoid. To the east, the passage between it and Duvillaun is quite clear, and any dangers near it are clearly visible.

Duvillaun's as seen from Inishkea Islands
Image: Tourism Ireland

At the western extremity of a chain of rocks that extend about 3 miles from Blacksod Point, lie Duvillaun Islands. These form the north side of the entrance to the bay. They are of moderate elevation, based on rocky foreshores, and generally foul to a distance of 400 metres. Duvillaun More, the largest of the group, is 50 metres high. Towards the west end of this chain of islands there is a narrow channel, Duvillaun Sound, through which boats may pass in fine weather. It lies between Duvillaun Beg and Gaghta Island. The beacons, astern on Inishkea South, kept in line 307°T lead through this channel. Those rounding outside Turduvillaun, should give it a wide berth, as there is a rock with 6.4 metres water, 300 metres to the west of it with rough seas and races in this area.

Duvillaun's (left) with Black Rock Island seen beyond Gaghta and Leamaereha
Image: Keith Ewing CC BY-SA 2.0

A vessel having once ascertained her position with reference to Achill Head or Black Rock light, may safely run for Blacksod Bay in any weather. In thick weather, however, when these objects have not been sighted, it must be approached with caution, as from the number of islands lying on the north side of the entrance it is sometimes difficult to identify it.

The coast to the north of Blacksod Bay is composed of sandhills with projecting reefy points. These are fronted by a series of outlying islands and rocks. Between this and the shore, there is a good safe channel, easily navigated by sailing vessels.

The Inishkea Islands used to have a Norwegian whaling station here in the early 1900’s. Remains of this and the deserted houses can still be seen. The southernmost of these islands extend for a distance of three miles in a direction nearly parallel to the shore. A narrow small boat channel separates the North Island from the South; at the inner end of which, and on the north side of Rusheen Island there is the Inishkea Island South Click to view haven anchorage for small vessels in fine weather, but the holding ground is not good. Vessels running in here must give the rocky point of Rusheen Island a good berth.

Distinguished by a round grassy hill with a flag-staff on it, South Inishkea has outlying rocks Carrickalaveen extending for ½ a mile to the south of it. Leamslug, a narrow channel with a least charted depth in the fairway of 11.7 m, lies between the south extremity of Inishkea South and the rocks extending 500 metres north from Carrickalaveen. It should be used only by small craft and with local knowledge.

Mullet Peninsula left with the Inishkeas seen offshore

Image: Adrian Weckler

A long and dangerous ledge, Pluddany Rocks, extend across the channel to a distance of ½ a mile from the southeast point of North Inishkea. In settled conditions, it is possible to pass between the Inishkeas and the Mullet Peninsula on the alignment of 198° T of Turduvillaun, the little western hummocky islet off Duvillaun More, and the Ears of Achill, 5¾ miles farther along south-by-southwest, as best seen on Admiralty Chart 2704. This alignment passes 300 metres east of Pluddany, the single danger along its path.

At the northern end of North Inishkea there is a cluster of rocks extending nearly a mile in the direction of the islands, with foul ground on their western side, but otherwise clear of danger. The chain of islands is interrupted here by a wide sound, in which there are two detached rocks, Usborne Shoal and Carrickmoneagh, having clear passages between them.

The primary danger is Usborne Shoal that lies ¾ of a mile north by northwest the northernmost of these islets of Inishkea North. Steep-to all round and with 2.7 metres of water LAT is usually marked by breakers but not always. When its position is shown by the breakers a vessel may safely pass on either side of Usborne Shoal. At other times the highest part of Duvillaun More touching the east side of Inishkea Islets, leads to the east of it. Likewise the alignment of due south (180° T) of the E extremity of Inishkea North and the 58 m summit of Duvillaun More.

The drying Carrickmoneagh, that dries to 1 metre, situated 1.3 miles to the northwest of Usborne Shoal, is always visible and clear of hidden danger. This makes the passage to the north of Usborne Shoal and between it and Carrickmoneagh, one of the best courses.

Lying ¾ of a mile to the northeast of Carrickmoneagh, and with a clear channel between them lies Duffur Rock. This is the southernmost of another group of rocks and islets, which are only separated from the low reefy shore of the main by a channel 600 metres wide, with a depth of 9.1 metres water.

The largest of this group, Inishglora appears in Irish legend as the resting place of the Children of Lir. It has some very old monastic remains on it and the islands are connected to each other by reefs, which extend to a considerable distance from them, particularly on their eastern side.

Lying a mile and a ⅓ to the north of Inishglora, and west by north, nearly a mile from Annagh Head, is Edye Rock with 2.6 metres of water over it. Two yellow buoys situated about ½ a mile to the southwest mark its position.

Edye Rock – Yellow buoy Fl Y. 3s and Fl(5) Y. 20s position: 54° 13.912’N, 010° 08.782’W

By not opening the red sector of light from the Black Rock, a vessel will pass nearly ½ a mile outside all these dangers. Eagle Island lights in line, leads well outside them all.

Vessels bound to the north, from Blacksod Bay, may pass inside the islands of Inishkea. In working inside the islands, the shore of the main must be approached with caution, as it is flat a long way off, and in standing towards the island be careful to avoid Pluddany Rock. Carrickmoneagh may be passed on either side at a distance of 200 metres. The tides run through these channels at the rate of 2 knots on springs, the flood going to the north.
Please note

Unless some interesting navigation is required a vessel should stand out to the west, clear of the islands by this passage, as there are no leading marks for the narrow channel inside Inishglora.

Rounding Annagh Head the Haven of Frenchport (Portnafrankagh) Click to view haven can be found. This is a convenient stopping point as it involves no deviation from the direct route around the coast.

Eagle Island stands about 3.5 miles to the west of Erris Head and ¾ of a mile from the shore. The island is 50 metres high and surmounted by a white lighthouse.

Eagle Island - lighthouse Fl (3) 15s 19M position: 54° 17. 012’N, 010° 05.502’W

Eagle Island is steep-to and clear of hidden danger. Inside it is the 21 metres high Cross Rock. Between this and the shore there is a passage 600 metres wide, with 37 metres water that a vessel may use in moderate weather and smooth water. 1¼ miles to the east of the island there is a small detached rock, called Carrickhesk, which rises to the height of 12 metres.

Erris Head, the northernmost tip of the Mullet Peninsula, is a well-known and recognised landmark by mariners and weather forecasters alike. The head terminates in a small cliffy island the 52 metres high Erris Head. Rocky Island is at the outer end of detached rocks that extend a ¼ of a mile to the north of it. Beyond this it is clear of hidden danger with more than 40 metres of water at the distance of ½ a mile.

What is the best sailing time?
May to September is the traditional Irish Sailing season with June July offering the best weather. June and July’s statistical incidence of strong winds are however two days of winds up to force seven. As such, depending on personal sailing preferences, a vessel may expect to be held-up or enjoy robust sailing conditions. Ireland is not subject to persistent fog. Statistically complete days of persistent fog occur less than once in a decade.

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