"Hurry, then. Swim to the north of the rock, and don't come up till you're on the other side. If you feel yourself rising, grab hold of the sea-weed, and keep yourself down till you've hauled round the rock. Quick!" There was a crashing in the bushes, not fifty yards away, along the cliff, as we dived into the clear green water. The plunge carried one further than I expected, and four or five strokes along the bottom of the sea brought me to the base of the rock. It was quite easy to turn it, and I was relieved to find that there was a good ledge for landing on the further side, only an inch or two above the level of the water, and quite screened from the island by the rock itself, which was about ten feet in length, and curved in a half-moon shape, with the horns pointing towards the mainland. In fact, it was like a large Chesterfield couch of stone, covered with brown sea-weed, and resolutely turning its back on the island. We were luckier than I had dared to hope; and when, in a few seconds, Duncan had coiled himself on the ledge beside me, I saw by his grin that he thought we had solved the problem of escape. For five minutes we lay dead still, listening to the clamor along the cliff from which we had just dived. "Thank the Lord, we get the sun here," said Duncan at last, as the sounds died away. "There's only one thing that worries me now. What are we to do when they come round in a boat?" "They won't think of that for some time," I said, "but when they do, we must take to the water again, and work round behind the rock. We ought to be able to keep it between us and the blighters, with any luck. We've only got to keep enough above water to breathe with; and I've seen some fine camouflage done with a little sea-weed before now." We looked at the yard-long fringes of brown sea-weed, and decided that it would be possible to defy anything but the closest inspection of our rock by the simple process of sliding down into the water and pulling the sea-weed over our heads, on the side next to the island. There was a reef which would prevent a boat passing on that side.