For his crew, Bud chose Mel Flagler and another man. Mel was an experienced jetmariner who had gone on the Swift expedition to Aurum City, the underwater ruins of a lost civilization. Here Tom had used his spectromarine selector to restore the ancient buildings.
Tom, Hank, and Arv went back to the airfield and soon took off in the diving seacopter. Landing on the water, they submerged and began the undersea detection test.
Tom manned the sonarscope personally, eager to conduct as careful a search as possible.
"Getting any blips, skipper?" Hank called out from his post at the Sea Hound's controls.
"Not a ping, Hank. The system seems to be working out even better than I'd hoped."
Tom felt a glow of satisfaction. He explained, however, that the jetmarine's transparent nose pane—which had to be left unprotected for the pilot's visibility—offered one vulnerable spot to sonar detection.
"But a little smart maneuvering can cover up that angle," Tom added. "Try the hydrophones, Arv, and see if you can hear 'em."
The chief modelmaker slipped on the earphones and listened intently. For another ten or fifteen minutes they probed about with no sound trace of the "invisible" jetmarine.
But presently Arv snapped his fingers to catch Tom's attention. "Got her, skipper!"
Tom took over the hydrophones. Sure enough, his ears could make out the faint hum of the jetmarine's atomic turbines. Tom directed Hank toward the sound, then ordered him to switch on the Sea Hound's powerful search beam.