Cheyne waited until the rush had past, and then rose to the surface. He found himself a few feet in advance of where he had dived.
He had not got many more feet when he heard the thunder of the roller on the rocks once more. Again he was under water before the bore entered the cleft. He had resolved to risk nothing, and his curiosity to know what his foe was like could not induce him to wait and see it.
This time the conditions below water were slightly altered. The passage was wider, and the hold, consequently, less secure; but, to compensate for this, the rush of water was less swift.
The fact that the passage widened thus gradually was a matter of surprise and much anxiety to Cheyne. He had a considerable distance to go before he got out of the cleft and within sight of the yacht, which lay to the southward a little off where he was.
If the passage went on widening as it approached the mouth, then there must be a point, and that too not far off, at which it would be impossible for him to reach from side to side, when, in fact, he would have nothing to rely upon but his powers as a swimmer. A baby would be as potent against that bore as he, if he depended on his powers as a swimmer merely.
It was necessary to proceed with the utmost caution. Should one wave overtake him, unprovided with secure holding-ground under water, all that he had hitherto achieved would be undone, and his own life most likely endangered. He must, so to speak, pick his steps. That is, thenceforth all his progress must be under water.
When the present bore had run its course he rose for breath. The period of his submersion was never more than ten to fifteen seconds. After a few hasty inspirations he dived again, and, feeling carefully along, crawled forward hand over hand, and foot over foot, for a few seconds, until it was time to expect the next wave. Then he set himself to resist it as before.
The moment the current slackened, he rose once more, took breath, and dived again.
At last he came to the place beyond which it would have been obviously unwise to advance, if he were to depend on the means hitherto adopted of stemming the torrent.
What was to be done now?