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!
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