Badly bent divers have to spend time in the decompression chamber which is a claustrophobic steel cylinder and the word is that if you don’t like confined spaces then don’t get bent. In the past nine years, 90 cases of decompression sickness have been treated with four deaths and many permanent injuries.

Sharks are another problem. The sight of half a seal floating past in the water is a bad sign and a very sobering sight. The seals themselves are a problem because of their inquisitiveness. When traveling flat out they look discomfortingly like a shark and have the habit of belting up to the diver like a Bondi tram and stopping dead with their snouts pressing against the diver’s goggles. Divers say that this makes the heart beat just a little above normal.