"Worth a try," Tom urged.
But the Sea Hound, too, had a serious drawback. Even with its powerful search beam sweeping the ocean floor as it prowled along, the explorers found their vision too limited.
Finally Tom said, "Bud, we could skin-dive at this depth."
"Let's give it a whirl," Bud urged.
The seacopter surfaced again, while the boys donned flippers, masks, and air lungs. Then they dropped over the side and made their way slowly downward into the gray-green depths, accustoming themselves gradually to the increased pressure.
"A lot more freedom of action," Tom thought. "If only we didn't have to communicate by signals!"
There was a sudden swoosh somewhere on his right. A projectile, Tom realized! Turning, his eyes widened in horror as he saw an uprush of bubbles.
Bud's air tank had been hit!