Bud helped the men on the hull for a while, then descended through the hatch to see how Tom was progressing.

"I'd go gaga trying to keep track of those circuits," Bud said, as he watched Tom installing the delicate transistors and other components with an electric soldering gun.

The young inventor grinned. "It'll be simple enough when the control unit's all put together," he replied. "Just a single on-off switch and one test circuit."

By noon, after working at a frenzied pace, the job was done. Tom thanked each one of the men personally. Then everyone went to eat lunch.

After the meal, Hank Sterling asked, "How about a detection test to see how she works?"

"Coming right up," Tom said. "Want to skipper the jetmarine, Bud?"

"Sure do!"

"Okay. Pick out a couple of men for a crew and take her down." Tom produced a hydrographic chart of the waters around Fearing and marked out a test area. "Cruise around there for an hour and we'll try to spot you in the Sea Hound."

"Hide and seek, eh?" Bud grinned and snapped a salute, then left to supervise the relaunching of the jetmarine.