These include the 'Grey Dogs' and the Gulf of Corryvreckan, in which is located the infamous Corryvreckan whirlpool, which is the third largest whirlpool in the world. It surrounds a pyramid-shaped basalt pinnacle, rising from a depth of   to  below sea level, at its rounded top. It is not unusual to find  high waves passing between the island at high tide.
The 'Grey Dogs' and the Gulf of Corryvreckan, home to the famous Corryvreckan whirlpool, which is the third largest in the world. The whirlpool surrounds a pyramid-shaped basalt pinnacle that rises from a depth of  to below sea level at its rounded top. High waves are frequently observed between the island during high tide.