Dundrum Harbour is located on the northeastern coast of Ireland, at the head of Dundrum Bay which is approximately midway between the entrances to Carlingford and Strangford Loughs. The small harbour is set into a tidal estuary and offers an anchoring pool adjacent to the old town quay.

The estuary offers complete protection when secured inside. Careful navigation is however required for access owing to a shifting sandbar at the entrance plus a narrow estuary access path. Hence the location is more suited to shallow-draft vessels and should only be approached on a rising tide, in settled sea conditions and with very good visibility.

A vessel should not approach Dundrum Bay in any developed onshore conditions. A considerable in-draught develops that is accompanied by a heavy seaway running into the bay. In these conditions, a sailing vessel could easily get caught within its heads and find it difficult to work out again. Southerly winds render the estuary impassable by creating a heavy sea on the bar. The approach to Dundrum Harbour passes through Ballykinler Firing Practice Area and must be avoided when the firing range is in use.

Keyfacts for Dundrum Harbour

Position and approaches

Haven position

54° 15.362' N, 005° 50.411' W

This is about the position of the anchoring pool set in the estuary channel off the old town quay.

What is the initial fix?

This waypoint is approximately 3 miles out from the shoreline and on the recommended 330° T line of bearing of Dundrum Castle. It is also on the outer 064° T white sector limit of the Saint John's Point auxiliary light Fl WR 3s 14m W15 R11M.

What are the key points of the approach?

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What's the story here?

Dundrum Harbour is a small tidal harbour situated at the head of Dundrum Bay. The head of the bay is composed of sand hills that are penetrated by a narrow channel which leads into the harbour. This then enters into a hammer-headed tidal bay where Dundrum Quay is located on the northwestern shore of the tidal inlet at the foot of a small round hill. Upon this hill are the ruins of an old Norman castle which are conspicuous from the bay. The old quay has an apartment complex which overlooks the estuary and a village with a population of about 1,500 stands behind it.




The sandbar which seldom has more than 0.3 metres of water on it is situated in front of the channel. However, this is very workable with a tidal range of MHWN 3.8m MLWN 1.8m MLWS 0.8m The quay and the wharf abreast of the village dry at low water but can be approached by vessels drawing up to 3.4 metres 2 hours before HW.




Drying out alongside Dundrum Quay is however not recommended as the northeast and south sides have deep gullies that could tip a boat over. The northeast side of the pier also has some rocks and the private dwellings here now reduce its usefulness as a pier. There are also strong tidal streams running along its face.

The best option is to anchor off in the tidal channel adjacent to the town quay where it is possible to find a pool to anchor in 2.1 metres LWS.

How to get in?

Seaward approaches are detailed in eastern Ireland’s coastal overview for Strangford Lough to Dublin Bay . Dundrum Bay is clear save for the northeastern section to the eastward of the always visible and easily identified Craiglea Rock where it is foul out for a mile in places.

Dundrum Harbour is entered through a narrow channel that leads between the sand dunes on the northern shore and should only be approached on a half and a rising tide in settled conditions.

Vessels awaiting a rising tide may find a temporary outer anchorage off the shoreline just under a mile and a half to the east of the entrance. This is situated 800 metres to the southwest of Craiglea Rock. Do not venture any further east as The Cow and Calf Rocks, Long Rock and the Pladdies are located. These are all part of a reef that extends to the southeast of Craiglea Rock and out 1.2 miles from the shoreline. Other alternates of Murlough Beach between Newcastle and Dundrum or in the bay, as indicated on the chart, inside of St John’s Point but be aware that bay is fringed by rocks.

If red flags are shown from flagstaffs on the south and east sides of the entrance to Dundrum Harbour it indicates firing is taking place. Then vessels in the bay must keep clear and south of the yellow oval buoys, marked "DZ" and FL.Y.5s & FL.Y.10s. It is still possible to enter Dundrum Harbour as vessels retain the right to transit the range for navigational purposes.

The range, D401, is used for small arms up to Mortar and Anti Tank weapons and the seaward side restriction is essentially a safety area for overthrows. The range control is not contactable but, if you need to cross the range when the red flags are being flown, you may proceed but be as expeditious as possible and do not anchor inside Craiglea which is on the range's perimeter. If you have concerns, you can call Belfast Coastguard on VHF 16 and inform them of your intended transit and they can contact the Range Controler on your behalf.

Finally, during winds from the west or northwest be watchful for sudden heavy squalls from the Mourne Mountains.


From the Dundrum Bay initial fix, track into the head of the bay on a line of bearing of 330°T of the ruins of Dundrum Castle. The castle is located on a small rounded hill behind the town. The estuary is best approached on this line of bearing, from the south-southeast. It does not lead in but positions the approach in the broad vicinity of the entrance.




The entrance is surrounded by shifting sand and is highly changeable. It is situated 3 miles in from the initial fix, 1 mile to the west of Craigalea, and 5 miles to the west of St John's Point. The greater part of it dries at low water and it is difficult to approach, so it is advisable to take it slowly, sounding in all the way.




It is not marked by any buoys but perhaps local boats may have some markers that might provide clues. Best to be prepared to sound in from the 5-metre contour and for grounding on the sand when entering or leaving the harbour.




Closer in, the outer end of the entrance channel will make itself known by the village with Dundrum Church becoming conspicuous up the centre of the entrance. The shoreline of the channel on the eastern side is grassy and embanked whilst the western side is wooded. There are firing range markers on the outer spit of the western side of the channel.



Once in the narrow channel, it leads 1¼ miles in a north-northwest direction. At its head pass close to port of the dilapidated post on the south side of the estuary and steer for the quay.




The quay has up to 3.4 metres 2 hours before HW but its unsure footing and strong tidal streams running along its face reduce its usefulness as a pier. However, subsequently berthing alongside after a low water survey could be practical.




Anchor off in the tidal channel adjacent to the town quay where it is possible to find a pool to anchor in 2.1 metres LWS. A large number of old moorings in this ancient harbour make a tripping line highly advisable. Expect strong tidal streams in the channel.

Why visit here?

Dundrum derives its name from the Norman Castle, in Irish 'Dún Droma', meaning 'fort of the ridge or long hill', the ruins of which sit dramatically above the town today. The castle was built on the site of an earlier fortified earthwork, from which the place-name 'Dún Droma' had long since established itself.




The ruins of the stone structure overlook today and was begun by John de Courcy, who led the 1177 Norman invasion of East Ulster. After Henry II recognised de Courcy’s conquests as the Earldom of Ulster, he built two major stone castles from which to administer his lands, Dundrum and Carrickfergus. The north Antrim territories were controlled from a large motte-and-bailey fort near Coleraine called Mount Sandel. Dundrum Castle was complete shortly before 1210 and during its Norman period, it steadfastly guarded the Norman’s eastern land route from Drogheda via Greencastle to Downpatrick. In its time Dundrum Castle was described as the most impenetrable fortress in the land, but being a key stronghold, it would change hands many times.




The castle passed to the Knights Templars in 1313, about the time the Order was abolished. At some point after 1333 it was managed by the Magennis clan, and is sometimes called 'Magennis Castle'. With commanding views south over Dundrum Bay, the Mourne Mountains, the lands west towards Slieve Croob, plus the eastern plains of Lecale, it was an important stronghold that the clan used to keep out the forces of the English Crown. This did not go unnoticed and the Earl of Kildare, briefly captured the castle by storm in 1517 as did Lord Deputy Grey in 1538. But the Magennises would retake it until they finally surrendered it to Lord Mountjoy in 1601. It was made over to Lord Cromwell in 1605 whose soldiers partly dismantled it in 1652 after they withdrew their garrison and sold it to Sir Francis Blundell. It was a ruin by the time the property passed to the second Marquess of Downshire in the early 19th century, though Sir Francis probably left his mark by planting the trees on the hill.




During his tenure, the Ulster ports began to rise in prominence when in 1625 William Pitt was appointed 'Customer' of the ports of Newcastle, Dundrum, Killough, Portaferry, Donaghadee, Bangor and Holywood. With his support, the fourth Marquis of Downshire invested extensively into improvements to the quay and added commodious storehouses which spurred on local development. The later arrival of the East Downshire Steamship Company became a further impetus to the harbour’s development. A railway connection reached Dundrum in 1869 and the sidings from the main Belfast-Newcastle line extended down to the quays.




Various cargoes were exported, most notably potatoes, but also sand that was obtained by barges near the bar at the inner bay mouth at low tide. Likewise, large-scale coal and timber imports came in here. The port strived to create a regular passenger service from Belfast via Dundrum to the British Railway harbour at Silloth in Cumbria, and Whitehaven. But the strictly tidal nature of the harbour would always frustrate the development of a regular passenger service. And sadly, after centuries of frenetic port activity the port would also fall victim to the rise of larger deeper ships and in 1984 Dundrum closed down as a commercial harbour. Soon after, the remaining East Downshire trading activities in the port ceased.




Today Dundrum is a much quieter place. It operates at a steadier pace of life where visitors come to relax. Dundrum Castle is today an important example of Norman architecture and it and its grounds were placed in State Care by the seventh Marquess in 1954. It is a regular destination for tourists and schoolchildren and is well worth a visit. The central circular keep, complete with a fine spiral stairway within its walls, fortified gateway and drum towers, all set on a moat and bailey, is still intact and accessible. Ascending the stairs within the keep, albeit a sturdy climb that requires some care, is very worthwhile. The views from the top over the surrounding countryside and out through the entrance channel to Dundrum Bay are simply stunning.




Very little remains to be seen of merchant past apart from the northern end of the former quay, where leisure craft berth. The warehouses and quays have now been redeveloped for housing which has greatly reduced the use of the quay for sailing purposes. What makes up for this is the area's several local walks. First off, do not overlook the third of a mile woodland walk along the Dundrum Castle Woods Trail if you do visit the castle. This is the first of many enjoyable walks to be had in this area of which the best are the Dundrum Coastal Path and the Murlough Nature Reserve which are easily reached on foot, walking from the village.




The Dundrum Coastal Path is a 2.5 km (1.6 miles) stretch of 'The Lecale Way' that runs along a disused railway line on the banks on the western shore of Dundrum Inner Bay. It follows the line of the old 'Belfast and County Down Railway' and, although potentially muddy after rain, it is relatively level and passes through a variety of terrains that provide many opportunities for bird watching.




The Dundrum Coastal Path scenery varies considerably in accord with the level of the tide. High tide is visually stunning, particularly on a clear calm sunny day when it feels like a riverside walk. At low tide, the bay becomes a vast sand and mudflat teaming with birdlife. Consequently, it is worth taking the walk at different tide levels to fully appreciate its many guises.




Walking out of the village to the south quickly takes a visitor to the edges of the National Trust’s 'Murlough Nature Reserve'. This is a 5,000-year-old dune system situated between Dundrum and Newcastle. Comprised of heathland and woodland that is surrounded by the estuary and the sea, it offers a variety of walks through the dunes and out onto beaches. At 697 acres, it is the best and most extensive example of dune heath within Ireland, with a network of paths and boardwalks through the dunes. The varied habitats within the reserve are home to a wide range of animals and plants including badgers, stoats and delicate flowers. The rich wildlife of this area changes with the seasons but there is always something of interest.




Near the entrance to Murlough Nature Reserve is the remarkable Slidderyford Dolmen that is a unique experience in itself. This Neolithic portal tomb is composed of four stones, two granite and two slate. It timelessly overlooks the Mournes with its massive granite capstone elegantly resting into one of the portal stones as if held in the palm of a hand. These long walks are also a good reason to treat yourself to some top-quality local seafood available in the town – for example, Dundrum Bay oysters with garlic and Cheddar crust.




From a boating perspective, Dundrum Bay is a perfect harbour for the shallow or moderate draft vessel and perfect for one that can take to the bottom. It has everything to hand in a stunningly beautiful tidal estuary surrounded by sand hills in which the small quiet town nestles. Although most of the imagery shown here was taken at low tide the estuary is at its best when the tide is high and the inner bay is a picturesque and pretty lake. So much so, that it warrants serious consideration for moderate draft vessels to see if they can find a pool to anchor and enjoy this truly lovely location.

What facilities are available?

With a population of just over a thousand, there is a small but useful selection of shops, pubs and cafes, plus a variety of dining opportunities that include award-winning restaurants. Almost all necessities are immediately available including fuel and a post office. Fresh water is available at the quay where a two tonnes grab crane is also situated.

Newcastle which is five miles away is located approximately 25 miles from Belfast, along the A24 road, and approximately 90 miles from Dublin. Bus 240 from Newcastle (10 minutes, seven daily Monday to Friday, six Saturday, four Sunday) to Downpatrick (15 minutes), stops in Dundrum
The nearest major railway Station is in Newry just over 25 miles away. Belfast International Airport is 30 miles away and Dublin Airport, over 85 miles, takes approximately 2 hours of travelling time.

Any security concerns?

Never an issue known to have occurred in Dundrum Harbour.

With thanks to:

Fred Curran, Custodian of Ardglass Marina.