There seemed to be great confusion on board the Shark. The boat was brilliantly lighted, and the conning tower stood high above the water. The ports on the side toward the Sea Lion were open, as if to admit the pure, cool air of the night.
"I believe there's something the matter with her air supply," Ned said to Frank as the two stood together on the tower. "The ramming she gave us must have done her a lot of mischief. Looks like she was stuck there until help comes."
"The help she ought to have is right here," Frank replied. "I'd like to get that crew on board a man-of-war."
"We have the real criminals," Ned replied.
The boys watched the Shark for a long time. They could see people moving about on the inside, and occasionally a group assembled on the conning platform, which was much larger than that of the Sea Lion.
"I believe some one is going down in a water suit," Ned said, presently. "The water chamber is on the other side, but she lists as if a weight was pulling at her."
"Listen!" Frank cautioned. "There's the machinery working. That would be the lowering apparatus. Some one is going down, all right. Now, what for?"
Ten minutes passed, and then the waters surged about the Sea Lion, and a great roar and rumble came with the waves which swept into the open hatch. The Shark, too, rocked on the crest of a great wave.
"Dynamite below!" Ned said. "Will there be more than one?"