There was a large living room and three bedrooms, each with twin beds.

In the rear of the cottage was a kitchen with kerosene stove and kerosene refrigerator. A fifty-gallon drum out back provided the fuel supply, which was piped in through copper tubing. Rick checked the fuel.

The tank was full. He read the simple instructions tacked to the wall over the refrigerator, then lighted the burner. There were frozen foods and soft drinks as well as dairy products among their supplies, packed in dry ice in the _Water Witch's_ food locker; the refrigerator would be cold enough for the supplies by the time the boat arrived.

For bathing in fresh water there was an outdoor shower, a shower head rigged to a five-gallon drum and supported on a frame of two-by-four wooden members. A canvas curtain gave privacy. Other sanitary facilities were equally primitive but effective.

Scotty opened the door of a lean-to shed on the rear of the house. "We can stow our diving gear in here. There's a bench, too. Looks as though the owner used the place for cleaning fish and stowing his fishing equipment."

They walked around to the front of the house where there was a small porch. A few wicker chairs were upended against the wall. The boys righted them and sat down.

"This is the life," Rick observed. "Look at that view."

They looked from the porch down to the sandy beach, past the pier and the Sky Wagon to water that was almost gla.s.sy calm. The water continued in a smooth stretch for about five hundred yards out to the reef. Light breakers foamed along the reef, and beyond, the water was a blue waste to the horizon. A quarter mile south, a break in the reef marked a pa.s.sage where boats could enter.

Somewhere, out beyond the reef, was the wreck of the _Maiden Hand_. In his mind, Rick planned how they would go about finding it. The first step was to rig some kind of underwater towing boards. Then he and Scotty, equipped with their aqualungs, would be towed behind the _Water Witch_, scanning the bottom as they went.

He wasn't worried about finding material for the towing boards. Any kind of planks would do, or they could even make a tow board out of a fallen log, although that would be harder to control.

"Come on," he invited. "Let's walk through the palms. We need a few planks, and we might as well get them now."

By the time the scientists approached the pier, the boys had explored the central part of the island and had returned to the cottage lugging planks found in the ruin of a cottage apparently blown down by some long-past hurricane. They dropped the planks beside the house and hurried to catch the line that Zircon threw, then they warped the _Water Witch_ in to the dock.

All hands turned to, and in a short time supplies were unloaded and stored, beds were made with linen and blankets loaned by Dr. Ernst, and the cottage began to take on an inhabited look.

While Tony Briotti began preparations for dinner, the boys carried their aqualung equipment to the shed at the rear of the cottage and began to check it over. Since their lives would depend on proper functioning of the equipment, they inspected the regulators carefully, checking the condition of the neoprene flaps. Once checked, the regulators were hung on nails on the shed walls, out of harm's way.

The next step was to inspect the tanks. Rick had already looked them over, but for the sake of safety the boys did it again. There were six of them, each of seventy-cubic-feet capacity. There was an advantage to this particular capacity at the depth where they expected to dive; a diver could work only fifteen minutes at 120 feet without requiring decompression, and seventy cubic feet of air would last just long enough. Double tanks would have meant the boys would be able to stay down nearly twice as long, but would also have meant the nuisance of waiting through the decompression period of about thirteen minutes ten feet below the surface on the ascent. For this reason, the boys planned to dive with single tanks, leaving the spares on the surface.

Of course, to get even fifteen minutes of diving at twenty fathoms the tanks had to be filled to capacity. When full, they were under enormous internal pressure of over two thousand pounds per square inch. The tanks had been filled at Spindrift, but the boys decided to check them again, in case there had been some leakage through the valves during shipment.

Scotty swung one tank upright and prepared to attach the pressure gauge.

Rick, inspecting another tank for b.u.mps that might have weakened the tank wall, saw him do it.

For a moment Rick continued his inspection, then what he had seen suddenly registered. He yelled, "Scotty! The valve!"

In that instant, as Scotty attached the pressure gauge, the valve blew out!

The entire valve a.s.sembly and the pressure gauge, propelled by the tremendous pressure in the tank, blew straight upward, ripping clear of Scotty's hand and taking a patch of skin along. The ascending a.s.sembly, traveling with bullet speed, clipped a lock of hair from his bent head.

[Ill.u.s.tration: _The valve a.s.sembly, traveling with bullet speed, barely missed Scotty's head_]

Scotty yelled, "Run!"

The tank, its air free to escape, writhed and turned, then fell over on its side. It was like an inflated balloon, turned loose to fly around a room. Air jetted from it with terrific velocity, so that the tank was, for the period while its air lasted, a true rocket.

It struck the wall of the shed and went through it like paper, smashed into a stud and caromed slightly, so that its trajectory was altered enough to drive it directly at Rick. He fell flat and it went over, just grazing him, then flew into the palm grove. It hit a palm a slanting blow and turned upward, shooting high in the air, clipping off the top of another palm as it went.

As the boys watched, horrified, it climbed straight up. Then, its high pressure nearly exhausted, it turned leisurely and plunged back into the grove, almost burying itself in the sandy soil.

The boys sat down and stared weakly at each other. For the first time, Rick noted that Scotty's hand was bleeding. He said shakily, "Here, let me look at that."

The scientists rushed out of the house and demanded to know what had happened. The tank had blown through its devastating course so fast that they had not even had time to get outdoors.

Zircon bandaged Scotty's hand with supplies from the first-aid kit while the boys told them what had happened. Tony said, "Very careless, leaving a valve loose like that."

Rick told him positively, "It wasn't left unscrewed, Tony. We always use a wrench on those valves because high pressure is so dangerous. And it wasn't like that yesterday. I checked the tanks when we stowed them on the boat."

Scotty gestured toward the other tanks. "Better take a look."

Rick did so, and gave a low whistle. The valves had all been loosened.

They were in place only by a turn or two of the threads.

"They could have come out any time," he said grimly. "Any rough handling could have knocked a valve out. And if it had happened on the boat, the tank would have gone right through the bottom or side. It was just luck Scotty and I weren't killed."

Zircon wordlessly found the valve wrench and got to work s.c.r.e.w.i.n.g the a.s.semblies back in place. The others watched silently, until Scotty said, "Well, at least we're out of St. Thomas. There won't be any more sabotage!"

CHAPTER VII

The Derelict

Rick and Scotty were up at dawn the next morning. They didn't bother with anything so prosaic as breakfast. Instead, they collected masks, snorkels, and flippers for a preliminary dip. They didn't use the lungs; those were to be saved for more important work than casual swimming.

For this first swim, each boy selected a spear gun. Scotty chose the same light spring gun he had used to save them from the shadow, while Rick took his favorite gun, a four-strand rubber-powered weapon that packed a terrific wallop. They belted on their knives and blew up their plastic floats. These were essential for resting, if necessary, and for bringing home their catch, if any. Once a fish was speared, it was important to get it out of the water as soon as possible, since blood would bring sharks or barracuda if any were in the neighborhood.

"Come on," Rick said impatiently. "Let's go."

"I'm coming." Scotty finished coiling up the light line he used to tether the float to his belt, and they stepped into the water. The temperature was just right. They ducked under, then put on their equipment. Scotty pulled a rubber glove over his injured hand. Pushing their floats ahead of them, faces down in the water, they started for the reef.

Rick watched the bottom carefully. It was clear sand, with no sign of life other than an occasional conch or other sh.e.l.lfish. This was to be expected, since marine life tended to collect around reefs, rocks, pilings, wrecks, and similar things. As they approached the reef, coral heads and outcroppings began to appear. And with them, fish.

Rick hooted for Scotty's attention, then lifted his head and let his mouthpiece fall free. "Let's go outside!" he called as Scotty looked up.

The other boy nodded agreement. Both were anxious to examine the reef.

The surf was light. They crossed over the reef by towing their floats and timing their movements through the breakers. Once beyond the point where the waves broke, the water was fairly calm, with only light surges from the pa.s.sing waves.

Rick looked down and saw the reef drop away under him. It shelved off perhaps twenty feet down, then beyond the shelf it fell away into the depths. He looked into the blueness with a stirring of excitement. To find the _Maiden Hand_, they would have to swim into that mysterious blue realm.

Scotty hooted. Rick looked, and followed the direction of his pointing arm. There, browsing around the shelf below, was a handsome red snapper, perhaps fifteen inches long. They had stopped in Miami and Rick had noticed that red-snapper prices were about the same as those for steak.

There was no doubt that the fish was very good eating. He gestured to Scotty to go after it, then floated motionless, watching.

Scotty put the loader over the tip of his spear and pushed down, c.o.c.king the gun. Then, without a splash, he slid under the water. Rick watched as his fins propelled him slowly toward the snapper. Scotty was moving slowly, because this was the prime rule in underwater hunting. As he swam, he extended the spear gun, aiming over the short barrel. The snapper stopped browsing and his dorsal fin suddenly erected, a sign of alarm. But he didn't move because he was not yet sure the big invader was an enemy. Before he could make up his mind, Scotty fired.

The spear took the fish right behind the gills. He gave a quick spurt that brought the line humming from its spool. Scotty followed quickly, caught the shaft, then sped upward to where Rick waited.

"Good shot," Rick complimented him as Scotty caught his float. Together, they took the fish off the shaft and examined him with some pride. Their first catch off Clipper Cay was a good one. The snapper was pink and firm-fleshed. He would make good eating.