If the tug struck and stopped, the white seas would beat her down into the sand.

In the meantime, she was using full steam, because, since tide and surf carried her on, one must have speed to steer.
The spray cloud got thick, and wavered with luminous tremblings when the long rollers broke.

They came up, spangled with green and gold flashes, from astern, shook their fiery crests about the tug, and vanished ahead, but one heard them crash.

Lister thought the tug throbbed to the savage concussion.

He could not hear his engines; one heard nothing but the daunting uproar.
By and by he felt a shock; not a violent shock, but as if the boat had touched, and was pushing through, something soft.