I stopped counting when I got to 37 dolphins. The jumping, diving, jostling pod had surrounded our catamaran like a gang of silver grey muggers, but my attention had been sidetracked by two bulky, menacing shapes to the left of the group......

A giant head broke the surface and a plume of spray erupted seven metres into the air. The head was followed by the graceful arch of an enormous back and, several seconds later, by a small curved dorsal fin...