Fastnet Rock
The world famous Fastnet Rock with its impressive lighthouse lies 5km southwest of the end of Cape Clear Island and offers some of the best diving anywhere in Ireland. As there are strong and sometimes erratic tidal flows and deep water all around the rock, it means diving at the Fastnet is only for the experienced and then only with reliable boats and very calm weather.
It is 15km from Schull and it is advisable to charter a hard boat for the trip to give extra security and to benefit from local knowledge. For those “going it alone”, two substantial dive boats,
both with reliable engines and radios should be considered the absolute minimum. As it is very difficult to assess the weather conditions around the rock from shore, be prepared to abandon the dive and head for a less demanding spot and keep a sharp watch out for changing conditions when the tide turns.
All that said, when the conditions are just right, a trip to the Fastnet can give you a day to remember for many years. The visible rock is in the middle of a narrow reef running SW-NE about 1km in each direction with depths of 45m being rapidly reached on either side should you get swept off by the tide. The section of reef towards Cape Clear is the simpler to dive on and close to the rock itself there is some shelter from the tide if you have missed exact slack water. The section of reef outside the rock should be approached with great care as the tide rarely stops flowing and the diving is very demanding. Being an isolated rock, the underwater scenery is spectacular with huge shoals of fish and fantastic growths on every rock face. Due to the clarity of the water and the excellent scenery it is easy to misjudge depths and durations, so don’t get too carried away!
A suitable method of spotting divers who have surfaced a long way from the boat must be used, though due to the deep narrow gullies and tidal flows, a SMB can be difficult to use effectively. If the sea is absolutely flat calm, it is possible to land on the rock and inspect the lighthouse at c lose quarters, to marvel at the high quality of the stone masonry which has withstood 80 years of Atlantic storms. This is only for those who are nimble footed and prepared to swim back out to a boat if the swell suddenly picks up!