The set of the current was a guide of a sort, but, as events proved, it misled them.

Man is ever prone to over-estimate, and such a slight thing as the lap of water across the bows of a small craft was sure to be miscalculated; they contrived to steer west, it is true, but with a southerly inclination.
At four o'clock, by general reckoning, they were mid-way between island and continent.

They were all wide awake, too weary and miserable to sleep.

Suddenly a fog-horn smote the oppressive gloom.

It drew near.
A huge blotch crossed their bows.