The contact bombs dangling from the sweep wires had struck against the submarine's hull and exploded, letting in the water at several points. The Hun seamen were even now drowning, caught without a show for their lives, just as they had probably sent many souls to graves in the ocean.
For some minutes more the dirigible moved back and forth through the air, her observers watching for the presence of hidden enemy craft. Then, without warning, came the message:
"Sorry, but engine trouble threatens and will compel our return to land, and to our base if possible."
"The best of luck to you," Dave ordered wirelessed back to these British comrades. "We'll stand by until we're as close to shore as we can go."
For he knew that, near shore, the shoals became dangerous shallows at this point on the coast.
Away limped the "blimp," the "Grigsby" following, and standing ready to do rescue work should the dirigible need assistance.
But the "blimp" not only made her way over to shore, but vanished slowly in the distance.
All of the mine-sweepers that had come up were ordered by signal to continue sweeping over the shoals.
"I want to see more of this work personally," Dave told his executive officer, who was now to be left in command. "Clear away one of the power launches. I'll take Mr. Ormsby with me."
So Dave was taken over to one of the mine-sweeping, snub-nosed craft that had formerly been a steam trawler on the Dogger Banks. The commanding officer, Hartley, proved most glad to welcome them.