At last, they reached a spot beyond which they could go no farther, as a deep passage was here broken in the rock.

But they were now beyond the line of breakers.
After several vain efforts to launch the boat, in each of which she narrowly escaped destruction, they agreed that the only plan was, after a wave passed, to drop her on to a flat rock, which then showed above the water, and to jump into her.
The two boys on shore were to hold the head rope, to prevent her being dashed towards the land by the next wave, while Larry worked with the oars to get her away from the ridge.

The moment the wave had passed under them, the head rope was to be thrown off.
This plan was carried out.

The two boys had but just time to jump into the boat and get out their oars, when the next wave lifted the boat high on its crest.

The lads holding the rope were nearly torn from the rock, but they held on till the strain ceased, then they threw in the rope, and Walter and Larry bent to their oars.
"Row easy, Larry," Walter said, as the next wave passed under them, "and put her head to each wave." Terrible as was the sea, the curragh floated buoyantly over it, though several times, as she rose to the steep waves, Walter thought that she would be thrown right over.