"Exactly."

"Good!" ejaculated Frank. "And where is our vessel, sir?"

"If you will look about a little you will see it," replied Lord Hastings.

Frank and Jack let their eyes roam over the broad expanse of the Thames, but they could see nothing but a few small boats of various sorts—nothing bearing the slightest resemblance to a ship of war.

"I don't see anything that looks like it, sir," declared the boy.

"That," said Lord Hastings, "is because you insist on looking too far away. You don't see it for the reason that you are sitting in it right now."

"What, sir?" exclaimed Frank. "Sitting in it now? You mean we are going submarine chasing in this motorboat?"

"Exactly," replied Lord Hastings.

"But, sir——" began Jack.

"You'll find," interrupted Lord Hastings, "that for submarine warfare there is nothing to equal the motorboat—particularly a swift motorboat such as this; and we are now on our way to join the fleet."