Diving & Snorkeling


A Scuba Diver’s Guide to Strangford Lough and Lecale Coast

Strangford Lough and the Lecale coast are well known as one of Northern Ireland’s top diving destinations, and rightly so!  The abundance and variety of its coastline and richness of biodiversity, geology, maritime archaeology and beauty prove to be an exciting and mysterious place for diving. 

This guide is designed to help divers decide which dive spot is best for them according to their ability, safety, equipment and of course their own personal passion, whether it be wildlife, wreck diving or under water habitats.  Also included in the guide is important information about access, tidal streams, and the dos and don’ts within the internationally protected site and fishing zones.

Entering Strangford Lough from the Irish Sea you are struck by the narrowness of the rock lined channel and the turbulence of its swift flowing waters (up to 8 knots) which scour the seabed. The appropriately named “Narrows” is just 0.8km wide south of Portaferry and 8km long, which varies in depth from 30m to 66m. As the current speed drops further into the lough, finer sediments cover the bed and shores. The finest mud and sand sediments can be found in extensive tidal flats, such as those at the north of the Lough. The Lough has a deep “y” shaped channel running up its centre but for the most part is less than 10m in depth, where around 70 islands and pladdies can be spotted at low tide. 

Strangford Lough is infamous for its tidal flows, whirl pools and overflows, so it can be a treacherous place for visitors and locals alike. Many a ship wreck has met its peril on the numerous hidden rocks and pladdies dotted over the sea bed. The Routen Wheel whirlpool, south of Portaferry, is characterised by heavy boils, whirlpools and short-lived but violent stoppers. It is caused by a ledge of rock only 4.6 metres below the surface, 200m south of Rue Point. The name "Routen Wheel" was given by the Vikings as they thought the sound of it was like cattle snoring.  The wheel occurs during both the flood and ebb tide although it tends to be more violent during the ebb. The turbulence lasts for about 400m so it is quite easy to avoid the wheel by keeping to the west side of the channel or hugging the coast down the east, but if you want to investigate more closely, the best time is on the flooding tide.   The bar mouth where the Irish Sea meets the lough can be equally violent, but is easily navigated in good conditions thanks to well placed markers and beacons.

Within the lough you will find that the tides will very much dictate how and where you access the water and dive with some dives only possible at slack water, which in the lough lasts a mere 15 minutes so good timing is essential. The tidal range within the Lough varies 4m at springs to 2.5 at neaps, with high water at the mouth of the lough differing considerably by around 2 hours when within the lough. 

Tides and currents vary along the eastern coast.  You can find useful information for each harbour at www.visitmyharbour.com 



These dive sites have been handpicked by local divers who have tried and tested and marveled at their habitats and species and underwater landscapes.  Star species include conger eels, beds of brittle stars and octopus!  As always please be aware of the currents in the Lough, you may only have a short window of opportunity so know your tide times.  Strangford is also a very busy place so always use an SMB to avoid any unnecessary collisions or getting lost!


dive sites



The drop off is a popular dive in the narrows of Strangford Lough. Here steep boulder slopes with areas of limestone wall drop to depths of over 60m, making it useful for divers wanting to build up their depth experience. It is sheltered in the narrows and therefore accessible in most weather conditions.

However, it can only be dived as a boat dive at high or low water slack. You can get as much as an hour slack window on neaps but much less on springs - it is usually possible to get two waves of divers in on neaps if you put the first wave in when the tide is slightly running.

Launch at Portaferry or Strangford and aim to be on site forty minutes before high-water or low-water and wait for the tide to slacken - it is advisable to have divers kitted up and ready to drop in when this happens to maximise bottom time.

The dive can be carried out on both HW and LW slack although if you are planning a long decompression stop it is better to dive the site at LW slack; on an ebb tide when the tide picks up divers are usually carried into Ballyhenry Bay but there have been incidences of divers drifting into the path of the ferry! Local divers report that there is a longer slack on low water neaps than high water neaps and the opposite on springs.

The white navigation tower on Ballyhenry island can be used as a marker for the site, if divers are dropped fairly close to this in about 15-20m they can progress to their chosen depth, the slope is fairly gradual to 25m and then very steep; consequently the dive is suitable for divers of all levels of experience (providing they can operate an SMB!). 

Boulders and bedrock outcrops are covered in a dense turf of dead men's fingers (Alcyonium digitatum), antenna hydroids (Nemertesia antennina), and squirrel's tail hydroid (Sertularia argentea). Look underneath boulders and in crevices in limestone walls and you are likely to spot spiny squat lobsters (Galathea strigosa), tompot blennies (Parablennius gattorugine), lobsters (Hommarus gammarus) and edible crabs (Cancer pagurus).  There is normally abundant fish life including cuckoo wrasse (Labrus mixtus) and goldsinny wrasse (Ctenolabrus rupestris). You may be lucky enough to spot a curled octopus (Eledone cirrhosa).

The Alastor, Ringhaddy Sound 

Ringhaddy is about a 20-30min boat ride from Portaferry/Strangford although obviously this will depend on the sea state. The boat can be reached from the shore

Empire Tanya, Ballyhenry Bay 

Used in D-Day landings after the war (1947/1948) the boat was purchased by the breakers yard ‘John Lee’ operating from Ballyhenry Bay. Whilst delivering the ship to the breakers, she struck a rock and sank and subsequently broke in two. The wreck does not have a permanent shot on

Inner Lees                                                                                                                                                                                                      The Inner Lees is the bow section of a large ship which is sitting upright in 12m of water only 5mins from Portaferry. As with the Alastor the Inner Lees can be dived from either the shore (100m fin) or a boat and at any state of the tide. This is an easy dive where the visibility is normally 2-4m. This wreck breaks the surface (except at high water) and so can be found easily without transits. It is an excellent dive for novices and experienced diver s alike. There is a lot of life to be found underneath the wreck particularly on the channel side. There are plenty of opportunities to enter the wreck and practice penetration skills, line laying etc. It would also make a superb night dive.

Outer Lees                                                                                                                                                                                                                  This is the stern section to the Inner Lee’s bow and is located further out into the lough meaning that it is only accessible from a boat, a journey which will take approximately 5-10mins from Portaferry. The wreck lies in 15m of water and will normally break the surface although it may be covered during HW springs. There can be quite a current on this wreck at certain times, so it is only diveable on slacks. The best slack period on this wreck starts approximately an hour and a half after Belfast LW or an hour and forty five minutes after Belfast HW and lasts for full ebb if on neap tides or for around 3hrs if on spring tides. Both the Inner and Outer Lees may be penetrated quite easily and so are ideal for training purposes.

Gun’s Island, Ballyhornan, Lecale Coast                                                                                                                                                        This is a scenic dive which can be dived at any state of the tide. The dive itself has a maximum depth of 16m and takes you around a small rocky outcrop which is close to the mainland. There are sheer walls on both sides, large boulders and the odd swim-through. As the sea-bed is made up of small stones the visibility can be quite good here as there’s not much silt to be kicked up. This dive is around 20-30mins from Portaferry depending on the sea state.

S.S. Georgetown Victory                                                                                                                                                                             The S.S. Georgetown Victory was built as a Victory Class troopship in 1945 in the U.S.A. In 1946 she left Sydney for Glasgow with 1,200 Royal Navy men and Marines due for demob after WWII. Inexplicably she mistook Strangford Lough for the Clyde and ran aground. Winter storms later separated the wreck into two parts. Some sections of the wreck were subsequently salvaged.



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