“Then—then you blow air out through your nose. The air pressure building up in the mask will force the water out around the edges of the mask.”
“Good. You both know the most important safety feature of skin diving. Okay, over you go.”
The boys slipped their swim fins, or flippers, on their feet and lowered themselves overboard. They sank slowly to the bottom.
At this point, the bottom was smooth, clean white sand. Biff and Derek moved around, using their legs and feet only for propulsion. Biff came up to Derek, circled his thumb and forefinger together, indicating that everything was going smoothly. Derek replied with the “V for Victory” sign. Then they rose to the surface.
When they broke water, Charlie Keene was waiting with another order.
“Down again, and as soon as you touch bottom, jettison your belts.”
Down they went again. Charles Keene was taking no chances on the boys’ safety and ability to skin dive.
Up popped the boys, their wet heads appearing above the water first and looking like strange creatures from the deep. Biff flipped back his face mask.
“Good work, Biff. But you’ve got to go back down and retrieve the weight belts. Here’s a spare. You’d find it tough to get down thirty feet without it.”
Derek climbed aboard the dory while Biff submerged to pick up the belts. He had to make two trips. The weight of three belts would have held him down.