The propeller was beating hard and he opened the throttle wide.

He felt her move and tremble, as if she struggled in the grip of the sand, and then lift buoyantly.

The water that pressed her down had rolled off the deck and the oncoming comber had picked her up and was carrying her along.
Her progress was obvious.

One felt the headlong rush, and Lister thought about a toboggan speeding down an icy slope.

The roller would bear her on until it broke, but if she struck the sand she might not lift again.
She did not strike; there was another wild leap forward, a savage plunge, and a comber crashed astern.