Above him in the conning tower Tim could hear Commander Ford conversing with Pat. Then the commander leaned over the edge of the tower and called to the men on deck.
“Everyone down below,” he said. “We’re going to submerge and run underwater to the Sea King plant. That may throw Sladek’s ship off our trail.”
They tumbled below, the main hatch was sealed, and Pat checked every gauge before Commander Ford gave the order to submerge. The S-18 went down twenty feet and then levelled off, the electric motors pushing it smoothly underwater.
With his eyes glued to a periscope, Commander Ford scanned the surface of the sound for another craft. At almost an instant’s notice the S-18 was ready to dive lower.
At the microphones, Ike Green was listening intently for the beat of the propeller of the tramp steamer. He grinned as Commander Ford entered the tiny room.
“They’re puzzled,” said the radio man, “and they’re zig-zagging all over the lower bay.”
The S-18 continued to run underwater at a bare four knots an hour. It was three hours later when they came to the surface and the sky was lighter in the east. Sunrise was less than half an hour away. To their left was the factory of the Sea King company and the S-18 nosed slowly toward the dock.
As the sky brightened they saw the smudge of a steamer well out to sea.
“Unless I miss my guess there goes Jack Sladek and his treasure-hunting expedition,” grinned Pat.
The seaplane purchased for their trip was on the dock ready and it took less than half an hour to load the craft on the deck of the S-18 and make it fast.