Strangford Lough

Boats launch from the slips at Portaferry or Strangford, and the Inner Lees lies only 5 minutes from Portaferry. The tides decide how and where divers get in, and some dives are only possible at slack water, which in the lough lasts a mere 15 minutes. For the Ballyhenry Drop-Off, boats aim to be on site forty minutes before high or low water and wait for the tide to slacken. The lough is busy, so an SMB goes up on every dive.

The Narrows are just 0.8 km wide south of Portaferry and 8 km long, varying in depth from 30 m to 66 m, and the swift water scours the seabed. At Ballyhenry steep boulder slopes and limestone wall drop past 60 m, the rock covered in a dense turf of dead men's fingers, antenna hydroids and squirrel's tail hydroid, with cuckoo and goldsinny wrasse normally abundant. The wrecks add penetrable hulls, and Gun's Island on the Lecale coast has sheer walls, boulders and the odd swim-through.

The lough is infamous for its tidal flows, whirlpools and overflows, and drift diving in the Narrows between Walter Rock and Cook Street Pier is dangerous and not recommended because the ferry uses that stretch. The lough and its coastline are a Special Area of Conservation, a Special Protection Area for birds and an Area of Special Scientific Interest, and byelaws prohibit diving in certain parts of it. Visibility can be questionable, with life hidden in sandy murk.

Strangford suits divers who are comfortable timing a dive to the tide and deploying an SMB. Novices have the Inner Lees, an easy wreck dive in 2–4 m visibility, and both Lees sections are used for penetration training. Divers building depth experience use the Ballyhenry slope, which is gradual to 25 m before it steepens. Divers who would rather not plan around the tide still have the Inner Lees and Gun's Island, both diveable at any state of the tide.