Grey Rock

The dive

Grey Rock is one of the boat dives worked out of Annaghvaan (Eanach Mheáin) in the island chain between Greatman's Bay and Kilkieran Bay. Galway Dive Club describes the practicalities first: you can safely anchor or tie the boat at the rock itself, where there is four to five metres of water. That shallow shelf is the whole of the site until you swim about a hundred metres south, at which point the bottom drops off almost vertically to around 38 metres. The further west along that edge you follow it, the deeper it gets, to a maximum of about 50 metres.

The wall is the dive. The club records an abundance of life on it including conger, lobster and crab, and singles it out as a good place for divers interested in smaller species — nudibranchs and the various corals that grow on tide-swept vertical rock. Records from this pin are dominated by exactly the fauna that fits: encrusting and branching sponges, sea squirts including light-bulb sea squirts and Ascidia, hydroids, the sea lemon nudibranch, and cuckoo, ballan and goldsinny wrasse working the face. It is a colour dive rather than a big-animal dive.

That depth profile is what makes it an experienced diver's site rather than a general one. A shot or tie-off in five metres and a swim out onto a face that bottoms at 38 m and continues past recreational limits to the west means the plan has to be made on the surface, not decided at the edge. Slack water and a marker are the sensible defaults: the National Parks and Wildlife Service records this whole bay system as subject to strong tidal streams where the sea funnels between the islands and through the channels.

Grey Rock and East of Grey Rock are two dives, not one, despite the pins sitting 240 metres apart. Galway Dive Club gives them separate entries with different profiles: the site east of the point 100 metres east of Grey Rock is described as an area for mid-range diving where the shore drops vertically to 27 or 28 metres, with plenty to see at various levels. If you want the deep face, come here; if you want a shallower wall, go east.

• Near-vertical drop from 5 m to about 38 m in one swim
• Sponge- and sea-squirt-covered wall face
• Conger, lobster and crab in the wall crevices
• Nudibranchs and cup corals for macro divers
• Boat can be tied off in 4-5 m on the rock itself

Conditions

A sheltered-looking anchorage on a rock in five metres of water, with a wall a short swim south of it. Conditions are governed by the tide running through the island channels rather than by ocean swell. Nobody publishes a visibility figure for the site.

On current: No source gives a measured current for Grey Rock itself. The neighbouring dive in the same club write-up, Gurraig Sound, is described as a drift where you cover ground at a fair rate, and NPWS records the Kilkieran Bay and Greatman's Bay system as subject to strong tidal streams as the sea funnels between islands and through channels. Treat this as tidal ground: plan the dive around slack, carry a delayed SMB, and keep the boat on you rather than at anchor if the stream is running.

Best months: May, Jun, Jul, Aug, Sep

Dives & underwater footage