The water was blown from the diving compartment and Gill and Graham struggled out of their diving suits.

Commander Ford called them to one side, and they conversed at length. Tim caught only snatches of the conversation, but it was enough to tell him that their situation was almost hopeless. Already the air inside the S-18 seemed heavy and his head ached miserably.

“How long can we last?” he asked Pat, who was standing by in the control room.

The chief officer shrugged.

“Let’s not think about that.”

The motors were shut off and the only sound was the faint humming of the ventilating fans as they forced a current of air from one compartment to another.

The crew, gathered in little groups, conversed in whispers. Joe Gartner, the gunner, battered open the top of one of the treasure chests and neat rows of gold bars were revealed. There was only a murmur of enthusiasm. Any man aboard would have traded a safe trip back to the surface for his share of the gold.

Commander Ford decided upon a desperate plane of action. A special bomb with a time fuse was rigged and Charlie Gill donned his diving suit again and went outside. They saw him working his way along the hull of the Southern Queen. Somewhere out there he would plant the bomb in the hope that the explosion would loosen the wreckage and allow the S-18 to shoot toward the surface.

Fifteen minutes later he was back. In five more minutes the bomb would go off. Tim literally counted every second. The crew waited at their posts and the motors were ready to push the S-18 toward the surface if they broke free.

The S-18 shook slightly. The propellers threshed madly, but there was no upward movement.