Not until within a cable's length of the shore could any opening be discovered by the keenest eye.

Then when the schooner was within her own length of the cliff her helm was put about.

She came round, and in a moment later disappeared.

An exclamation of surprise broke from all on board the brig, for they now saw that instead of the cliff stretching in an unbroken line it projected out at one point, and the precipitous headway concealed an extremely narrow passage behind it.
A moment later the brig imitated the maneuver of the schooner and passed in between two lofty cliffs, so close that there were but a few yards to spare on either side of her.

Fifty yards ahead the channel made a sharp turn again, and they entered a basin of tranquil water three or four hundred yards across.