The divers all came from old diving families and passed the art on to their children, receiving high pay and a regular scale of compensation to their families if they were maimed or killed by sharks or barracuda. He laughed at the idea of a diver killing a shark in deep water – he’d never heard of it – but he lost on average thirty men a year! But if we were interested in giant fish, there were seas on his charts marked where his tiny vessels were forbidden to go because the water was comparatively shallow and haunted by enormous octopi. He had actually lost two of his boats which had been capsized and pulled under by these monstrous brutes that in size went up to 10 metres long in the body, and had tentacles of eighty metres; these two ships were sucked down in full view of about twenty other vessels in the area! Sometimes they had been able to shoot some of these creatures, because at night they floated on the surface, apparently sleeping.

In deeper water, down to 200 feet, they used great inverted glass tanks that were sent down to the bottom of the ocean on the same principle that a teacup held upside down, but level, can be pushed under water and still keep the air inside it. Of course, the pressure of the air inside it was regulated from the surface, and the normal precautions against ‘bends’ had to be taken. Inside the glass cage – and the glass was 18 inches thick – were powerful arc lamps that brilliantly lit the immediate floor of the ocean bed and sent a sepulchral aura round to the range of about twenty yards. Sometimes sharks or swordfish swam into the glass not realising it was there, and dazzled by the light that intruded on their submarine kingdom. Also inside the glass tank was a long bench to lean or sit on, and all round it were wire shelves which held the oysters which the divers literally picked up off the sea bed. At these depths, oysters reached up to two feet across, and were as heavy a weight as a man could carry.

On each ship was equipment for opening the oysters, only about 20 per cent of which contained pearls, the big pearls, as might be expected, being in the oldest and biggest oysters. Until they were opened up on board, they were kept in sea-water tanks.