They were friendly bushes.

He remembered how glad he had been to grasp them when he made that run from the surf, and to some extent they had protected him from the cold wind when he lay among them like one dead.
The big rollers, white at the top, were still thundering on the beach, and directly in front of him he saw a lowering hulk, that of the schooner.

The slaver's wicked days were done, as every wave drove it deeper into the sand, and before long it must break up.

Robert felt that it had been overtaken by retributive justice, and, despite the chill that was shaking him, he was shaken also by a great thrill of joy.

Wet and cold and on a desolate shore, he was, nevertheless, free.
He began to run back and forth with great vigor, until he felt the blood flowing in a warm, strong current through his veins again, and he believed that in time his clothes would dry upon him.