CHAPTER VII
PORPOISE TAG
"Good grief! I'm trapped!" Tom squirmed desperately in a vain attempt tofree himself.
The ion-drive unit had hurtled to the far end of the tank at the firstflick of power. But its exhaust tube was still jetting out a current ofwater with stunning force. Tom could feel the near-crushing pressureagainst his chest, even the full length of the tank away!
"H-h-help!" Tom gasped.
Moments dragged by with agonizing slowness. Tom felt as if his lastounce of breath were being squeezed out by the viselike pressure.
Suddenly a gravelly Western voice reached him, singing "Home on theRange." It drew closer, swelling into a foghorn drone as the lab doorswung open.
"Good old Chow!" Tom thought. "Thank heavens!"
The grizzled, bowlegged cook ambled cheerfully into the laboratory,pushing a lunch cart. But, to Tom's dismay, he cast only a passingglance at the figure in the tank.
_Tom squirmed desperately to free himself_]
"Soup's on, son!" Chow announced loudly. He began to ladle out a bowl ofoyster stew from a steaming pot. Evidently he had not realized the younginventor's dilemma!
"Extra good today too, if I do say so myself!" the old Texan went on,setting out the rest of the lunch. "Well, come on, buckaroo! Break awayfrom them chores an' dive in! Brand my cactus salad, if there's onething that riles a cook--"
Summoning all his strength, Tom croaked out weakly, "Chow!... Get help!"
At the strange sound of Tom's voice, Chow jerked around. His eyes buggedout at the look on the young inventor's face. Then he dashed to thepublic-address outlet on the wall and switched on the mike.
"Help! Help!" Chow yelled. "Tom Jr.'s trapped in his lab!"
The roly-poly chef was quivering in panic. He dashed across the room andpaced helplessly about the tank. Within moments, excited men werecrowding into the laboratory.
Mr. Swift, among the first to arrive, took in the situation at a glance.He dashed to the control board and slammed shut the main switch, thuscutting off power to the ion-drive jet.
"Whew! Th-thanks, Dad!" Tom's chest was heaving as he gulped in air torelieve his tortured lungs.
Tom Sr. helped him climb out of the tank.
"B-b-brand my rhubarb rockets," Chow stuttered. "What in tarnationhappened?"
"Guess I gunned my new skin-diving jet a bit too hard," Tom saidsheepishly. "It was almost a K.O. for me!"
Mr. Swift asked Tom about the invention. After explaining how it worked,Tom added with a grin, "Maybe you'd better hang around, Dad, until Iinstall some sort of density-control gadget for my hydrolung. Then I cango up or down, or stay at any level easily."
Such a device, Tom felt, might prove to be a lifesaver if he should everbecome trapped under water--perhaps far from help.
The elder scientist chuckled and threw an arm around Tom's shoulders."I'd say you could design something like that with your eyes shut, son!"
Warmed by his father's appreciation, Tom set to work improving hisdiving apparatus.
An hour later Bud came bursting into the laboratory. "Hey! What's this Ihear about your getting hammerlocked by a water jet?" the husky youngpilot asked. He had been on a test flight and just returned.
Tom laughed good-naturedly. "Nothing serious. In fact, I felt prettysilly," he told his chum. "I souped up our ion-drive gizmo a bit toomuch."
Bud picked up the slender metal cylindrical assembly from the workbench."This it?" he asked, his curiosity immediately aroused.
Tom nodded and demonstrated the device in the test tank.
Bud whistled with glee. "Boy! With this rig, we can scoot around like apair of barracudas!" he exclaimed. "What about that other thing you'reworking on?" Bud pointed to a small electronic chassis on the workbench,studded with a tangle of transistors, diodes, and condensers.
"It's a density-control device," Tom explained. "A substitute forballast tanks, you might say. It'll enable us to rise or sink to anydepth at will, simply by varying our underwater density."
Tom said the device would be carried in a small case, hooked to thediver's belt, with a single tuning-knob control. The "throttle" or speedcontrol for the ion drive would be housed in the same unit.
"I can't wait to try out the new diving gear," Bud said excitedly.
By four o'clock Tom had the apparatus perfected, and turned it over toArv Hanson for fast duplication.
"We'll give it a shakedown tomorrow morning," he told Bud.
The duplicates of the ion drive and density control were ready andwaiting when the boys arrived at the plant next day. They immediatelyflew to Fearing Island and embarked in a motor launch, with Zimby Coxagain at the helm.
This time they cruised out to deeper water. Tom and Bud donned flippersand belt, and helped each other strap on his ion-drive jet.
"_Down_ we go, into the wilds of sharks!" Bud chortled lustily. "Watchyour step, Tom."
"Just make sure you come up again in one piece," Zimby said with a grin."Also, don't get carried away with that ion squirt gun and take off on around-the-world underwater cruise."
"Who knows?" Tom joked. Adjusting his face mask, he plunged over theside. Bud followed.
Down they glided into the sea-green wilderness. Leveling off in sight ofthe ocean floor, they tried their drive jets. The effect was thrilling!_Zip ... Whoosh!_ They darted to and fro like human torpedoes.
Then Tom twirled the control knob of his density unit. Immediately hebobbed upward like a cork. A reverse twirl sent him plummeting towardthe bottom again. Bud, watching with wide-eyed excitement, beganexperimenting on his own.
Soon the boys were engaging in all sorts of underwater acrobatics.Presently Bud felt a nudge in the back that sent him hurtling a dozenyards through the water.
"Snuck up on me, eh, pal?" he thought with a chuckle. "Okay, Tom oldboy, here's where the undersea terror strikes back!"
Swooping around to return the compliment, Bud gulped in surprise.Instead of his chum, he found himself face to face with a bottle-noseddolphin!
"Good night!" Bud thought. "A porpoise! So you're the joker who nudgedme!"
With a playful toss of its comical-looking snout, the porpoise swam off,as if inviting Bud to join in the fun and games. A whole school of thecreatures cavorted into view.
"Okay! If you want to play!" Chuckling, Bud darted in pursuit, whackedthe porpoise that had nudged him, and jetted off again. The porpoisegave chase, whistling and grunting audibly.
Tom joined in the fun, and soon a rollicking game of underwater tag wasin full swing. The dolphins seemed as playful and mischievous as smallchildren.
Twenty minutes later the boys surfaced and hauled themselves aboard.Both tore off their masks and flopped into the boat, shaking withlaughter, surfacing and diving.
"What was so funny down there?" Zimby asked.
When Tom told him about the dolphins, he too burst into laughter. Theporpoises rose into view and convoyed the launch all the way back to theisland.
The boys were so jubilant over the performance of the new hydrolung gearthat Tom decided to press his search for the Brungarian sea-prowlersimmediately. Soon after lunch they took off in the _Sea Hound_ andheaded for the South Atlantic. Hank Sterling, Chow Winkler, and twocrewmen accompanied the boys.
Dazzling afternoon sunshine sparkled over the sea when they reached themissile search area. Tom immediately contacted Art Wiltessa and thetask-force ships. They had no new developments to report.
The young inventor gave orders to submerge. As soon as the seacoptertouched bottom, Tom and Bud swam out through the air lock with theirhydrolungs.
They probed about for half an hour, ranging farther and farther from the_Sea Hound_. Then Tom felt a touch on his arm. He turned and saw Budpointing off excitedly to the right.
A strange submarine was moving slowly toward them!