"But a submarine couldn't carry a large enough crew to conquer a steamer."
"They wouldn't need to," said Homer. "It would be enough to send one man aboard to demand the treasure."
"Well?"
"The submarine could lie to, with her submerged torpedo tubes pointing full at the vessel. If within a given space of time the treasure was not shipped and the pirate lieutenant returned safe, a torpedo would be fired which would send the steamer to Davy Jones with all hands. As a captain is more responsible for the lives of his passengers than for their gold, he would have to consent. One might easily get half a million dollars from one of the larger vessels. Three or four cruises of that kind would be quite enough, and our friend, the imaginary pirate captain and all his crew, could retire from the profession."
"But do you really think such a thing is possible?"
"It's very unlikely," his friend replied, "but there's no doubt that it's possible. Several submarines have been sunk in the Great War, and one or more of these might be fished up by wreckers. Being hermetically sealed, no water would have got in, and their machinery would be as good as ever, even if they had been lying under the water for some months. As for crew—if the pay were big enough, there would be always enough desperate fellows to be found to make the venture. Yes, that plan is feasible enough. And, what's more, it would be hard to stop. Really, the more you think of it, the more possible it seems. The only weakness is the coaling."
"It seems to me," Eric said, "that if she could coal at sea, sink the ship and tow the boats containing the crew within reach of land, she would be pretty safe."
"Yes," his friend answered, "if she could stay at sea indefinitely until treasure enough had been accumulated, I believe a submarine could get away with it. There might be difficulty afterwards in getting rid of the bullion and the jewels, but, after all, that's a different question. It has nothing to do with the piracy."
Eric peered into the darkness, putting his hand over his eyes as though to look intently.
"Pirate, ahoy!" he called softly. "Three points off the starboard bow!"