3 adjectives to describe breakwater

There was a grim abutment at least eighteen hundred feet high; at its base two rocks, which had tumbled ages ago from the summit, formed a rude breakwater; and on this barrier had collected a bed of coarse pebbles, strewn with driftwood.

She reached it at a point where the cliff dwindled into flatness, where the gentle tide rattled on pebbles instead of on sand, where the tall breakwaters contradicted the line of the shore.

On beyond were the hulls of the ships sustaining their grove of masts and smokestacks and, at the extreme end, the yellow breakwater and the sky recently washed by the rain, with flocks of little clouds as white and placid as silky sheep.

3 adjectives to describe  breakwater