He moved over the level bottom, looking for lines which would indicate that the Shark people were out watching the movements of their rival, but found none. When he came to the end of his line he signaled for the submarine to go ahead.
In this manner, by slow degrees, and always keeping his eyes out for creatures similar to the one he had vanquished, he advanced until he saw the bulk of the Shark only a short distance away. Then he called for a stop.
He remained there some moments, watching the Shark lift to the surface. Then a dark object passed shoreward, and the boy was certain that a boat had been sent to the little wharf.
"I guess that will be about all," he thought. "I've secured the information Ned wants, and may as well go back."
To tell the truth, he was delighted at the thought of getting out of the water again. His encounter with the serpent had considerably lessened his enthusiasm for deep-sea work.
The Sea Lion dropped down when Jimmie gave the signal, and he was soon in the water chamber, where he found Frank in sea dress. The two were out of the water in a short time, with the chamber empty again.
"What did you do that for?" asked Jimmie, as soon as the helmets were removed.
"Do what?" asked Frank, with a smile.
"Drop down and wait for me in the water chamber."
"Did you notice the color of the water?" asked Frank.