I ought to have mentioned that we carried a large whale-boat, and about half-a-dozen frail little "shell" boats for the use of the divers.
The comings and goings of the various pearling expeditions were of course regulated by the weather and the state of the tide.

The captain himself went out first of all in the whale-boat, and from it prospected for shells at the bottom of the crystal sea.

The water was marvellously transparent, and leaning over the side of the boat, Jensen peered eagerly into his sea-telescope, which is simply a metal cylinder with a lens of ordinary glass at the bottom.

Some of the sea-telescopes would even be without this lens, being simply a metal cylinder open at both ends.
Although they did not bring the objects looked at nearer the vision, yet they enabled the prospector to see below the ruffled surface of the water.
The big whale-boat was followed at a respectful distance by the flotilla of smaller boats, each containing from four to six Malays.

When Jensen discerned a likely spot through his peculiar telescope, he gave the signal for a halt, and before you could realise what was going to happen, the native divers had tumbled out of their boats, and were _swimming_ in a weird way down to the bottom of the translucent sea.