"Let's go," he said. "We'll trade these for bacon and eggs."
It was nearly noon before they got into the water again. The first part of the morning was spent in fashioning sea sleds from the planks the boys had gathered. This was simple enough, but it took a little time. First the planks were cut to proper length, then two of them were nailed together. A bridle was arranged so that they could be towed, and spare weight belts and weights were used to counteract their bouyancy. They were very much like the aqua-planes commonly towed behind motorboats, but much cruder, and designed to go under rather than remain on the surface.
Two long ropes were arranged so that a sled could be towed on either side of the Water Witch. Once this was done, the boys rechecked their equipment, attached the regulators to the tanks, and carried them to the beach.
Zircon would pilot the boat, following the 120-foot mark on the chart. Tony would act as tender at the stern, while Rick and Scotty would ride the sleds. The first leg would take them through the reef channel, then south to the tip of the island, reverse course and north again, staying at the twenty-fathom mark. Zircon was sure that he would be able to follow the prescribed course by judging his distance from the reef.
When all was in readiness, they loaded their gear aboard the Water Witch, including the spare tanks. Only the runaway tank was missing, and Rick had determined that its wild flight had not weakened it. The valve and pressure gauge had been recovered after a considerable search, and the tank could be refilled with the others.
Zircon took the Water Witch through the reef, and the boys donned their equipment while Tony swung the ladder outboard. Rick checked his own straps, and then those of Scotty, while Scotty returned the favor. Then each checked the flow of air through his mouthpiece, and made sure the reserve rod was in the "up" position. This done, they entered the water. Tony tossed the boards over and made sure the lines were secured.
Rick and Scotty paddled the boards to the extreme length of the lines, then separated as much as the lines allowed. They were about thirty feet apart and a hundred feet behind the boat.
They waved their readiness to Tony, who relayed the go-ahead to Zircon. The boat started slowly.
Rick moved forward on his board, and the weighted board tilted down. It acted as a hydrofoil, its forward motion pulling it deeper into the water. Rick waited until he was only ten feet from the bottom, then shifted his weight back again. Obediently the board tilted upward and raced for the surface. Rick moved forward again just in time to keep from breaking through the surface. By adjusting his weight, he could keep the board level, or go up or down. It wasn't easy and he had to fight the board level almost constantly.
Bubbles rose from the regulator between his shoulder blades as he breathed rhythmically. The lung performed effortlessly, giving him as much air as he needed. He felt the pressure on his ears as he steered the board toward bottom, and there was an instant of pain before his ears adjusted.