What is the route?
Why sail this route?Blasket Sound is a very attractive option for a leisure craft passing north or south along this coastline as it cuts at least twenty miles off any passages between Valentia and the River Shannon. It is also very easily navigated being, at its narrowest point, ½ mile wide and having the benefit of a natural leading line on the mainland’s coastal features. This makes daylight pilotage through the sounds fairway very straightforward and it provides a convenient route that avoids the extensive rocks and shoals that lie to the west of Great Blasket.
Photo: Tourism Ireland
In reasonable weather, with fair wind or tide, Blasket Sound is the preferred leisure boat passage. But, in unsettled weather or at night, with its exposed position, uneven bottom and strong tides, it is best to pass to the seaward of the island group and its dangers. Likewise, its tidal streams can be confused and unpredictable at times so a vessel taking this route should be able to avail of reliable engine.
Tidal overviewToday's summary tidal overview for this route as of Friday, July 30th at 07:53. The speed of the tidal streams in the main channels varies but is generally about 1 to 3 kn that can cause occasional overfalls and eddies. As such it is advisable to make a transit with a favourable tide or at least before it reaches its maximum rate.
Tides in the Blasket Sound turn in line with the channels. The flood streams northward commencing at HW Dover -0120 (Cobh +0430), and ebb streams southward commencing at HW Dover +0440 (Cobh -0035). The tide turns approximately half an hour ahead of the local HW and LW which is approximately Cobh -0110. Sustained southerlies make the flood run for longer and stronger.
South Going Stream
(HW Dover +0430 to -0130)
Starts in 00:42:57
(Fri 08:36 to 15:01)
North Going Stream
(HW Dover -0120 to +0440)
(Tidal flow )
Ends in 00:52:57
(Fri 02:46 to 08:46)
What are the navigational notes?
Middle Blasket Sound waypoint, 52° 6.234' N, 010° 30.043' W
Safe mid-point fix to Blasket Sound passage
► Next waypoint: 1.51 miles, course ⇓ 15.34°T (reciprocal ⇑ 195.34°T)
Northern Approach to Blasket Sound, 52° 7.689' N, 010° 29.393' W
This is the point where a southbound vessel picks up the alignment, or a northbound vessel breaks off transit to clear Sybil Point’s outliers.
► Next waypoint: 2.94 miles, course ⇓ 355.28°T (reciprocal ⇑ 175.28°T)
½ a mile west of Sybil Points outliers, 52° 10.614' N, 010° 29.787' W
This is ½ a mile west the Maher-aneig rocks off Sybil Point.
Navigation through Blasket Sound revolves around making a passage of about 5 miles on the alignment of 015° T of:
- • The old tower on the summit of Sybil Point situated 4.5 miles north of the narrows
- • Clogher Rock lying close off Clogher Head, two miles south westward of Sybil Point
Sybil Point terminates in a bold precipice which rises to a height of 206 metres. The tower may not be easily identified from the south, but the summit on which it stands is easily picked out to provide the leading mark.
Photo: Tourism Ireland
The rugged 113 metres high Clogher Head lies about 1.7 miles south of Sybil Point. It has the prominent and sharply pointed above-water Clogher Rock close off the head.
Photo: Graham Rabbits
These in line lead through the centre of the narrows and then a ¼ of a mile east of Beginish Island and its surrounding dangers.
Photo: Burke Corbett
From the south, keep centre alignment at all times particularly at the narrowest point of the sound, between Great Blasket Island’s Garraun Point and Dunmore Head where the fairway reduces to ½ a mile.
Photo: d_marino2001 via CC BY-SA 2.0
Once past the narrows, the passage becomes partially sheltered by a large number of rocks and islets that extend a mile northward from Great Blasket making for a much more comfortable run.
In the area between Blasket Sound and Sybil Point, there can be a nasty race in west or northwest winds over the north-going tide. In fine weather, in the absence of a heavy swell, this presents no problem
At the ‘Northern Approach to Blasket Sound’ waypoint, the vessel is abeam of the north ends of the groups Connor Rock, about a mile to the west, with open sea ahead. From here it is time to depart the transit and continue northward to clear the Maher-aneig rocks that extend a ⅓ of a mile off the steep cliffs of Sybil Point. Southbound vessels should just apply the reverse.
Vessels should be prepared for sudden and violent gusts of the wind, that comes off the mountains and high islands in this area.
Image: Michael Harpur
Those with a little time to spare may take the opportunity to visit Great Blasket . Close northwest of Garraun Point and upon the shore facing the mainland, there is a beach called An Trá Ban. In fine weather, a vessel may anchor off the beach in 3 metres over a sandy bottom and land on the beach.
Photo: William Glasgow Howe