Near the southern point we were suddenly alarmed at noticing an alteration in the colour of the sea, which led us to suspect the proximity of a sand-bank. Nevertheless a boat, lowered to try for soundings, found no bottom at 45 fathoms. In fact, the water was found to be transfused with an enormous mass of _crustaceæ_, and small brownish filaments of 1/48 to 1/12 of an inch in length, occasionally collected into a knot, which rendered it cloudy and muddy, and at once explained a phenomenon at first sight so unexpected. Towards 5 P.M. we passed the southern point of the island, and somewhat later discovered a well-sheltered anchorage on the S.E. side of the island. Considerable anxiety was felt as the sun went down, since the boat that had been dispatched not only had not rejoined us but was not yet even visible. As soon as darkness had fairly set in, blue lights were burnt on board the frigate, of which the third was at last responded to by the crew of the boat, which had been provided with port-fires for such a contingency. It seemed to be steering for the frigate. Hour after hour, however, flew by without its approaching us, and the rest of our signals remained unanswered. Thus morning broke, and still no boat was visible. At length, about 7.30 A.M., the anxiously expected little wanderer hove in sight at a little distance, and half an hour later she came alongside all safe. The projected operations had been only partially successful, owing to the extreme difficulty in making a landing. Surprised by nightfall, it was no longer practicable to make out the ten nautical miles at least they were still distant from the frigate, and the scanty crew consequently saw nothing for it but to anchor close in with the shore, and await the light of dawn in the boat. The cause of our later blue lights not being answered, was partly the want of a sufficient supply of signal lights, part having been already expended, and the rest having got damp.