That it was not the mouth of a river was made clear by the presence of a current so strong that his men had to exert themselves to the utmost to prevent the boat being literally sucked into the channel by the powerful tide, which apparently was at its full.

This opening,--the water rushed into it so swiftly that he was satisfied it developed into a gorge farther back from the coast,--was approximately two hundred yards wide, flanked on either side by low lying, formidable bastions of rock.

The water was not more than fifty feet deep off the entrance to the channel.
Gradually the prow of the Doraine swung around and pointed straight for the cleft in the shore.

The ship, two miles out, had responded to the insidious pressure of the current and was being drawn toward the rocks,--at first so slowly that there was scarcely a ripple off her bows; then, as she lumbered onward, she began to turn over the water as a ploughshare turns over the land.
At precisely six o'clock she slid between the rocky portals and entered a canal so straight and true that it might have been drilled and blasted out of the earth under the direction of the most skilful engineers in the world.
Soundings were hastily taken.

Discovering that the water was not deep enough even at high tide to submerge the vessel when the inevitable came to pass and she sank to the bottom, Captain Trigger renewed his efforts to release the anchor chains, which had been caught and jammed in the wreckage.