The shadow's head turned toward Scotty, and Rick left the ground in a wild spring. He struck the shadow, hand clawing for the gun. He found a wrist, and twisted, falling backward as he did so. The shadow, the entire weight of his own body on his wrist from the throw, screamed!
The gun landed on the ground. Rick let go and scrambled for it, but Scotty was there before him.
In the instant of the struggle the stranger had hesitated on the window sill, hand grabbing for the pistol he had tucked in his belt. He pulled it free and aimed at the struggling figures below, but in the gloom there was no way to distinguish friend from foe. And in that heartbeat, Scotty picked up the shadow's gun and fired one snap shot.
The stranger's gun dropped to the ground and he fell backward into the room.
Scotty thrust the pistol into the shadow's stomach. "Face the wall," he ordered. "Put your hands against it. Now support your weight on your hands."
The shadow did as ordered. Rick took the man's legs and pulled them backward so that the shadow's whole weight was against his hands, his outstretched body forming the hypotenuse of a right triangle. The only way he could move to regain his balance was to lower himself to the ground and then get up.
Rick picked up the stranger's fallen pistol and hefted it. "Better see about the one upstairs," he advised. "I'll watch this one."
"I fired at his hand, but I was high," Scotty told him. "He got it in the shoulder. He won't get far."
Zircon and Briotti charged around the corner of the hotel in pajamas and slippers, followed by other guests and members of the hotel staff.
"We had a little trouble," Rick explained briefly.
The scientists took in the situation at a glance.
"As I said," Tony Briotti muttered. "Adventure-prone. And lucky! How do you beat a combination like that?"
Steve Ames walked into the hotel dining room accompanied by a young Navy lieutenant. He spotted the boys immediately and waved.
Rick breathed a sigh of relief. "There he is."
"We can turn this whole business over to him and then get out of here," Scotty returned.
The events of the night before had culminated in two phone calls, one by the hotel manager to the police, the other by Rick to Steve Ames. However, the duty officer at the UDT base had replied that Ames was not available. Rick had then asked for intelligence, and his query had gotten fast results. Steve Ames didn't show up, but Navy Shore Patrol officers did. The SP's had conferred with the local police, and the affair had ended with the shadow and the stranger, whom Scotty had potted in the shoulder, being carried off by both groups. First, however, the senior Shore Patrol officer had listened to their story, then instructed the boys, "Wait for Steve Ames. Talk to no one else. The police won't ask any questions."
After conferring, the Spindrift group decided to go ahead with their plans. The scientists were anxious to transfer their activities to Clipper Cay, not only to get on with their vacation, but to get the boys away from the mysterious danger that dogged their footsteps in Charlotte Amalie.
The scientists had departed at dawn in theWater Witch, after extracting a promise from Rick and Scotty that they would not stir from the hotel until Steve Ames contacted them, and that they would then fly at once to Clipper Cay.
The wait had been a long one. It was now nearly noon, and the boys, hungry because their breakfast had been at daybreak, were ordering lunch.
Steve Ames sat down and motioned the lieutenant to a seat. "Jimmy, this is Rick Brant and Don Scott. Boys, Lieutenant Kelly. Have you ordered lunch?"
"We were just looking over the menu," Rick replied.
"Fine. We'll join you."
The four consulted menus, then ordered. Steve turned to Kelly. "Jimmy, being the athletic type, you've probably never heard of the Spindrift Scientific Foundation."
The lieutenant, a heavily tanned young man with crisp black hair, shook his head. "Sorry. I never have."
"Well, it's a reputable, highly competent and conservative group of some of the best scientific brains in the country. But somehow, these two got attached to it. They're not very conservative, although they're competent—especially at getting into trouble."
Kelly gave the boys a comradely grin. "If he talks that way, he must like you."
The boys grinned back. The lieutenant was likable.
"All right. Last I saw of you two, Rick was lying across the legs of the guy who had been tailing me. The next thing I heard, two men we've been keeping an eye on were in the hoosegow, one with a slug in his shoulder. And I also heard some wild tales of jumping out of windows. Now fill in the details."
Rick started from the moment they first noticed that a shadow had picked them up. He told the story in careful and accurate detail, knowing that Steve's trained mind might find significance in things that meant nothing to him. Now and then Scotty elaborated on a point.
When Rick concluded the recital, Steve cupped his chin in one hand and stared at them thoughtfully.
Kelly complimented them. "Sounds as if you took care of things like real professionals, both in the water and in the hotel. And I must say, I wish my people would learn to give reports like that."
The boys thanked him, and Scotty added, "I don't suppose you can tell us anything about what you do?"
"Sure I can. I'm not one of Steve's hush-hush crew. I'm a simple Navy lieutenant."
Rick chuckled. "In other words, you can't tell us."
Steve said, "He's executive officer of the UDT group here. And he's group intelligence officer. I might also add that he's brighter than he looks."
"Then what do you make of this business?" Scotty inquired.
"I'm not that bright," Kelly replied. "Seriously, this one has me stumped. First of all, it's easy to understand why a shadow picked you up. After all, it must have been obvious that you knocked Steve's tail off. So they simply picked you up instead, hoping that you'd lead them back to Steve, or that you might be important in some way they couldn't understand."
"It's nice to have someone do my thinking for me," Steve said. "Carry on, Lieutenant."
"Aye, aye, Sir. The tail stuck with you. When your party split in two, he decided to stay with you instead of Zircon and Briotti. There could be two reasons: First, you were the ones who contacted Steve on the street. Second, you stayed at the waterfront while the others went off in a taxi. I like the second reason better because of what happened later. How about you, Steve?"
"I'm with you. Go ahead."
"Well, at this point I get lost. You put on your gear and swam out, not with any particular destination in mind, but looking for a rock or a coral head or something of the kind where you could see fish. The shadow watched you. Suddenly he got excited, grabbed a boat, and tried to run you down."
Steve grinned at the boys. "In fact, he got so excited that he stole a boat right out from under the owner's nose. What do you think of that?"
Rick scratched his head. "We'd about decided he was either desperate or stupid. I guess he was both."
Kelly continued. "The big point is, what made him desperate? It could only have been one thing, as I see it. You were getting close to something, and he was afraid you'd find it. So he lost his head. That's borne out by the remark his pal made last night, that he'd pulled enough stupid stunts for one day."
"But what could we have been getting close to?"
"I don't know. Whatever it was, it isn't there now."
Scotty and Rick sat up straight. Scotty demanded, "How do you know?"
Steve smiled. "Because a team of Navy frogmen went over the entire area inch by inch this morning."
At the boys' surprised looks, Kelly explained, "You told the Shore Patrol enough to get us interested. We put teams in the water at daylight. There's nothing there."
"But there could have been," Scotty pointed out. "If they suspected we knew about it, they could have removed it yesterday afternoon or last night."
"Correct," Steve agreed. "They were worried, too. Otherwise why the call on you last night? And the questions?" Steve paused while the waiter served them. "The conclusion is this: Something they value was in the water near where you swam. You met me yesterday morning, and they had already identified me. Which means that they must have agents in Washington who warned them JANIG was moving in on the case. Since it's no secret that I'm with the outfit, they could peg me easily. When you swam out toward this object, whatever it was, they were convinced that somehow JANIG had learned about it. The tail got desperate and tried to knock you off. Then, last night, they tried to find out what you knew, and how."
"Who are 'they'?" Rick asked.
"If I knew that, I'd wrap the case up and go home. Jimmy has been working on it for a week, but he hasn't any answers yet. I've been here twenty-four hours, and I know even less."
"Could you identify the two men?" Scotty queried.
"Yes. Both small fry, both local. And both are obviously green at this kind of business, otherwise you'd be a pair of real cold turkeys by now."
That was true, Rick knew. Experienced agents wouldn't have given him and Scotty the chances that they'd seized.
"The men must know what was under the water," Scotty said.
"Not necessarily. They just knew it was important, and they may have been ordered to protect it. But your former shadow was on the griddle all night, and told all he knew. It wasn't much. He didn't even know who had hired him. He wasn't stalling, either."
"What's the next step?" Rick wanted to know.
"Jimmy and I will drive you to the plane. Then you take off for Clipper Cay. And stay there until your vacation is over. Have you a short-wave radio, by the way?"
"Yes. Why?" Rick had an all-wave battery portable.
"Monitor the Navy command frequency. Here, I'll write it down for you. Listen every night at six for five minutes. If I want you, I'll send a message. I don't think I will, but it won't do any harm to set up a schedule."
Steve lowered his voice. "Now listen to me. This thing is big. The two you ran up against yesterday were not good samples. We're dealing with some tough professionals. I don't know who they are, but from what I've seen I can tell you they're dangerous. So you two are to stay out of this case. That is an order. Stay on Clipper Cay and have fun."
"I can add a small note to that," Lieutenant Kelly said. "I'm new here. I was ordered down from Norfolk only a week ago. A first-class intelligence officer had my job. He turned up in a hospital in the British Virgins after being missing for two days. He had a fractured skull. He still doesn't know what happened to him, and neither do we."
"Okay," Steve said flatly. "I appreciate the way you handled things yesterday, but that's the end so far as you are concerned. Get out, and stay out! And that's final!"
The Sky Wagon droned smoothly through a series of figure eights as Rick and Scotty inspected every inch of Clipper Cay and its surrounding waters. While Rick flew, Scotty marked off landmarks on the chart of the island that Dr. Ernst had provided.
"I wish we could spot the wreck of theMaiden Hand," Scotty remarked.
"Too deep," Rick said. "We can't see bottom at twenty fathoms even in water as clear as this."
"I've got everything important marked. What say we land and look over our property?"
"Okay. I'll shoot the beach while you look for coral heads. We don't want to snag a pontoon."
The boys had already identified their house. It was set at the edge of the palms, about fifty yards inland from the beach. It looked fine. There was a small dock to which theWater Witchcould be tied up when the scientists arrived.
Rick estimated that Tony and Zircon would arrive about sundown, two hours hence. The boys had flown over theWater Witchen route from St. Thomas. Apparently the scientists were enjoying the trip. Zircon had been sprawled in the cockpit while Tony trolled for fish.
"I'm a little surprised there wasn't something wrong with the plane," Rick observed. He and Scotty had gone over the Sky Wagon from propeller hub to rudder, fearful that the unknown enemy might have sabotaged the plane. But there was no sign of any tampering. However, the inspection had taken so long that it was late afternoon before they got away. It was significant and perhaps a little ominous that Steve and Jimmy Kelly had assigned a pair of husky Shore Patrol men with .45-caliber sidearms to stay with them until the plane actually took off.
"Maybe the two men who came after us were acting without orders," Scotty replied. "Maybe the real brains of the gang aren't even interested in us."
"I hope that you're right. See any coral heads?"
Although most coral growth was limited to the reef area, outcroppings of coral called "heads" had grown up toward the surface in some places. There were none in the stretch of water before the beach house where Rick planned to land.
"The water's clear. Pick your direction. There's not enough wind to make any difference."
"I'll land parallel to the beach."
Rick turned south down the center of the island. When he had reached the right position he cut the throttle, and the nose of the Sky Wagon dropped. He banked tightly, reversing course, until the plane was headed north a hundred yards out from the beach. He let the plane feel its way toward the water, then felt the first bump as the pontoons touched. In a moment they were down, and Rick swung the plane to taxi in toward their new home.
Scotty was already stripping off his shoes and socks. As the pontoons touched bottom a few yards from shore, Scotty climbed out. Rick cut the gun while his pal pulled the plane up on the beach.
Rick got out and waited until Scotty slipped his shoes on again, then they walked to the cottage.
The door was unlocked. Few people came to Clipper Cay, and locks weren't considered necessary. The boys pushed open the front door and walked in.
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 theWater Witch'sfood 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 glassy 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 passage where boats could enter.
Somewhere, out beyond the reef, was the wreck of theMaiden 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 theWater 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 theWater Witchin 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 bumps 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 assembly 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 assembly, traveling with bullet speed, clipped a lock of hair from his bent 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 screwing the assemblies 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!"
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 shellfish. 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 passing 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 theMaiden 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, cocking 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.
Rick put his face down in the water again while Scotty secured the catch to his float. As he did so he saw a target and hooted for attention. Scotty joined him and they looked down to where a barracuda hovered motionless.
The 'cuda was perhaps two and a half feet long, not big as such predators went, but big enough. Scotty motioned to Rick to get him. Obviously the fish had been attracted by the blood or the struggles of the snapper. Rick hoped that his big brothers wouldn't join him. This one was plenty big enough. While Scotty held both floats, Rick charged his gun, pulling back the strong rubbers a pair at a time. Then he checked his safety line, filled his lungs, and went under.
The barracuda hovered, waiting. Rick knew that his apparent disinterest could change to lightning flight. Few fish were so fast. He followed Scotty's example, moving slowly toward the quarry. He was a dozen feet down now, and in the lessened light the barracuda loomed large, a slim arrow of a fish, poised for flight.
The spear gun was extended, the spear point nearing firing range. Rick planned to shoot from about six feet. He doubted that he could get closer. Flippers propelling him gently, he closed. Now he could see the pointed jaws that contained razor-edged teeth. The fish was watching him, but without apparent fear.
The barracuda head was squarely in his sights. Rick squeezed the trigger.
For a moment he thought he had missed, then the safety line ran out and the jerk almost pulled the gun from his hands. He was running out of breath, too. Quickly he planed for the surface, feeling the fury on the end of his line. He broke water, gulped air, then dove again. He pulled in the line until he saw the fish struggling. He had nearly missed. The harpoon had taken the barracuda near the tail, fortunately hitting the spine. Rick pulled him in, hand over hand, then gripped his spear by the extreme end. He had no desire to close with those slashing, dangerous jaws. Holding fast to the spear he shot to the surface again. Scotty was waiting, knife in hand. As Rick extended the spear toward him the keen knife flashed across the 'cuda's spine just behind the gills. Rick tossed his gun onto the float, then together they heaved the fish up beside it.
"Spindrift was never like this," Scotty said, grinning.
Rick gulped air and grinned back.
A hail from the shore reached them. They turned and saw Tony Briotti. He was waving a frying pan in a signal for breakfast. Suddenly Rick realized that he was famished.
"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 theWater 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 theWater 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 theWater Witchthrough 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.
The bottom was sandy. To his right he saw the wall of the reef, and once a startled snook shot out of his way. To his left he could see Scotty. Before he knew it the boat had throttled down, a signal that they were at the southern end of the reef. He tilted upward and surfaced.
Tony called, "How is it?"
"Great!" Rick called back. "But we'll need lots more line. It was shallow on the way down, but if we try to go any deeper the angle of the line will make the boards come up."
"You should try it," Scotty said. "Honestly, Tony, it's wonderful!"
"I'll try it a little later," Tony promised. "I'm giving you all the line we have, about three hundred feet each. If you can't make it, surface. We'll have to splice the two lines together and use just one board."
Zircon came to the stern and bellowed, "You forgot these!"
He tossed in two fishing floats and coils of line. Those were in case they found the wreck. Whoever spotted it was to drop off his board, secure the line to the wreck, and let the float rise to the surface. In that way, they would have a guide.
Each boy took one of the units and fastened it to his weight belt.
"We're off!" Zircon called. "Ready?"
The boys yelled that they were. Rick fitted his mouthpiece and checked the seal of his mask. Scotty did the same, then both tilted their boards and slid under.
On the northbound leg they had trouble keeping the boards down because of the tendency of the lead rope to pull the front of the boards up, but by crawling far forward, they managed.
They were deeper than they had ever gone before, but Rick felt no sensation of fright or strangeness. It was a green world, not dark but yet not bright. The light was subdued, filtered by the fathoms of water. The bottom was mostly clear sand, dotted now and then by patches of growth. There did not seem to be many fish, or perhaps their eyes were not adjusted to the subdued light. Scotty was close to the reef on the northbound leg, while Rick was about twenty feet farther out.
For long moments there was only the sensation of rushing through the water, the distant throb of the engines, and the sound of their own bubbles. Then, ahead, Rick saw a mass of growth and tilted his board upward just in time to clear it.
Scotty hooted once, then again. Rick turned in time to see his pal's board leap ahead, free of Scotty's weight. Sudden fear gripped him. Had Scotty been caught? Instantly he released his own board and saw it scoot for the surface. He reversed his course and swam rapidly back.
The obstruction he had cleared was dead ahead. And there were fish! So many that they seemed like a swarm of flies around it. The biggest was not more than five inches long. Then he saw Scotty. His friend was fastening the float line to a projection!
Rick's heart leaped. What he thought was a rock formation on the sea floor was the wreck of a ship! Scotty had recognized it and dropped off. TheMaiden Hand? He hooted and Scotty looked up. The other boy shook his head.
It wasn't theMaiden Hand, then. But how did Scotty know? In a moment, when he joined the other boy, he saw the curling edges of steel plate. This was a steel ship, then, and not a very large one at that. He estimated its length as not more than a hundred feet. Still, it was a wreck—their first. There, at twenty fathoms, he and Scotty shook hands solemnly while the tiny fish swam around them like curious gnats.
Scotty finished tying his line and unwound it from the wooden spool. The float rose upward and vanished far overhead. They heard the throb of the returning boat, and Rick hooted twice, the signal to surface. Scotty nodded, and they went up, slowly, careful to breathe naturally and not to overtake their small bubbles, as doctrine dictated. In a moment Rick saw the hull of the boat, propellers barely turning, and knew that Zircon was holding position overhead.
They broke water off the side of theWater Witch, and Rick waited until Scotty hailed the scientists. "We found a wreck, but it's a steel ship."
"Come aboard!" Tony called, and helped them up the ladder when they complied. The tanks were cumbersome when out of the water.
"It's a fish paradise!" Rick said excitedly. "I'm going to get my camera working and take some pictures. You've got to go down and look, both of you."
"How did you spot it?" Zircon asked.
"Scotty did. I thought it was a rock formation and went over it, but Scotty dropped off."
"I saw curled plate," Scotty answered. "I knew it wasn't theMaiden Hand, with steel sides, but I didn't think we'd want to pass up a wreck."
"You were so right," Rick agreed, grinning.
A check of their tanks with the gauge showed that only about five minutes diving time remained at the twenty-fathom depth, so the regulators were transferred to spare tanks. Tony and Zircon, already in trunks, donned diving gear and followed Scotty's line to the bottom. The boys waited impatiently, Scotty taking the helm to hold the boat in place.
Ten minutes later the scientists surfaced, and Rick helped them aboard. Tony removed his mask and grinned. "It's as wonderful as you said it was."
"What kind of ship was it?" Rick asked.
Tony had been a destroyer skipper during the war and he knew ships.
"Probably an interisland cargo carrier of some kind. At any rate, it appears to be a small cargo ship. It's so overgrown with marine growth that the shape is cluttered. It might have been a small tanker."
"We can explore it from stem to stern," Rick suggested excitedly.
Scotty joined them and commented, "But not right now. We'll have to go ashore and charge the tanks. There may be time for one more dive this afternoon if we hurry."
"Besides," Hobart Zircon said with a smile, "I'm hungry. As you say, Rick, diving certainly develops the appetite!"
They docked, and Tony and Zircon went off to see about preparing sandwiches. The boys decided that rather than carry the tanks back and forth from the pier to the shed, it would be more sensible to bring their small, portable gas-driven compressor to the pier.
Scotty went after it while Rick tied the tanks to the afterrail of theWater Witch, in position for filling.
A yell from Scotty stopped him. He looked up and saw his friend beckon, and ran down the pier to the house. The scientists joined him and Scotty at the shed where the compressor had been stored.
"We've been sabotaged again," Scotty told them flatly. "There's oil in the compressor!"
"Are you certain?" Zircon pressed close to examine the machine.
"Yes. I stumbled over my own feet and tipped the compressor on its side. And oil ran out through the air fitting. Look!" Scotty held up his hand, and it was smeared with glistening oil.
A cold shiver traced its way down Rick's spine. Oil in a compressor was blown into fine particles, too small to be seen. If they got into an air tank they would be breathed in, leaving a thin coating on a diver's lungs. The result was a condition almost exactly like pneumonia, called "lipoid pneumonia." Their special filter, designed by Zircon, probably would have taken all the oil particles out of the air before it got into the tanks, but that didn't alter the fact that faced them. Someone had deliberately put oil in the compressor. Someone just didn't want them around!
"The question is," Rick stated, "when was the oil put in? While we were at Charlotte Amalie? Or while we were out hunting the wreck just now?"
"In Charlotte Amalie, of course," Tony said. "Why do you think it might have been done just a little while ago?"
Rick shrugged. He had no answer to that. The question had popped into his mind unbidden.
"We didn't take the compressor apart," Scotty reminded him.
That was true. But Rick had started it in Charlotte Amalie to be sure it was functioning. There was no oil in it then. He said as much.
"You started the compressor at the same time you checked the tanks," Zircon reminded him. "I believe the oil was put in at the same time the valves were loosened."
That seemed reasonable. Rick put aside his hunch. "Well, we found it in time, anyway. Now Scotty and I will have to tear the compressor down and clean it before we can recharge the tanks."
"After lunch," Tony said. "Don't you remember? A diver is supposed to rest after each dive. Relax, and I'll have some sandwiches ready in a few minutes."
All hands were hungry. Scotty stowed away four sandwiches and Rick did nearly as well. Then they started work on the compressor. It wasn't a hard job, but it was tedious, and nearly two hours elapsed before they finished. Each part had to be washed in soap and water, then carefully dried. Finally, the compressor was ready. They carried it to the boat, started the gas engine, and connected the tanks. But before the air started to flow, Rick carefully inspected the filter system to be sure that hadn't been tampered with too.
"You know," he observed, "these enemies Steve is hunting know a lot about sport diving."
Scotty considered. "They knew that tanks could be dangerous, and they knew that oil in a compressor is dangerous. You're right, Rick. They know plenty about it."
"But it doesn't do us much good to know that they know," Rick concluded. "Well, now what? It will be a few hours before all the tanks are charged."
"Where are Zircon and Tony?"
"Napping. We probably should join them."
"Not me. There's nothing to do after sundown but sleep. I'd like to take a walk and look the island over."
Rick sighed. "Always an eager beaver. I'll go with you, if you don't walk fast."
They turned north and walked up the beach. Somewhere off this stretch of beach was theMaiden Hand. But where? They strolled along leisurely, stopping now and then to examine some bit of beach flotsam. There were shells, but most of them were small and water worn.
"We'll have to collect a few shells on the reef," Rick said. "Barby will be disappointed if we don't."
"That's easy enough to do," Scotty replied. "I saw half a dozen different varieties this morning."
They passed a beach house, obviously empty. Rick gestured toward it. "Funny how few people there are here. If I owned a place on this island I'd be here all the time."
"Unless you had to make a living," Scotty added practically. "This isn't the season for vacations. I expect vacation time finds plenty of activity here. There's one cabin occupied to the south of us. I saw people there this morning. They're probably the same ones who waved at us from a boat when we flew over day before yesterday."
"The boat isn't there now," Rick observed. "At least, I haven't seen it."
"They may have gone to St. Thomas for supplies. Or they may have gone home." Scotty pointed to what seemed to be the largest house on the island, near the northern tip. "That's quite a place. Let's go have a look."
There was a long pier in front of the house, and, unlike the others on the island, this house had a second story. There was no sign of life. They walked around it and found a barbecue pit. Scotty examined it. "This has been used recently, probably in the past few days."
Rick bent down and peered at a scrap of meat. "You're right. They had steak. And this piece hasn't dried out yet."
"Maybe they're still here." Scotty walked to the back of the house. "They might be out fishing or something." He looked in a window and called urgently, "Rick! Look!"
Rick hurried to his side and peered in. The room was evidently used for storing diving equipment. Hung along one wall were three full diving suits of expensive make. Next to them, neatly racked, was an assortment of spear guns, all of the spring type, and all of Italian make.
On another wall were three Scuba regulators, not aqualung types such as the boys used, but the variety that carries a full face mask through which the diver breathes. In a rack on the floor were nine spare tanks and a compressor much larger and more expensive than theirs.
Swim fins, also of Italian make, were lying on a table. They were the shoe type, put on like a pair of slippers. Rick identified an underwater camera, complete with steering fins and outside controls, and a number of face masks with built-in snorkels. Boxes stacked on the floor carried labels that identified them as midseason suits of French make.
"We've found some real fancy frogmen," Scotty observed. "This place looks like a high-priced show-room for diving gear."
"Pretty plush," Rick agreed.
They wandered back down to the beach and found that this area of the island was apparently more open to the sea. There were bits of flotsam, including coconuts that had washed in. The sea shells were larger, and they found a few worth picking up.
Scotty beckoned and pointed to a piece of wood, nearly buried in the sand. "What do you make of this?"
Rick examined it. It was curved, and a shred of green metal still clung to the rusty remains of an ancient hand-fashioned nail. He looked up with sudden excitement. "It's a section of a ship rib. And a pretty old one, too." His finger indicated the shred of metal. "Copper. Or used to be." He broke it off. "Completely oxidized. It's been in the water a long time, perhaps even centuries."
The boys stared out at the reef, both half afraid to put their thoughts into words. Finally Scotty asked, "Do you remember reading about any earthquakes or big tidal waves down here recently?"
Rick tried to recall. "No. Why?"
"Well, theMaiden Handhas been under the water out here for a couple of centuries—and in pretty deep water, too. It would take some disturbance that could reach down a hundred and twenty feet to break off a chunk."
Rick grinned. "You're right. But we haven't anything to lose by taking a look, have we?"
They trotted down the beach toward their own house at a half run. Rick looked at his watch. "At least one pair of tanks should be full by now, and there's plenty of time for a dive. Come on!"
They paused at the pier, put the pressure gauge on the first two tanks in series, and found them charged, as Rick had predicted. Then they ran for the house.
Zircon and Tony were gone and there was a note on the living-room table. "We're exploring the southern end. Be back in an hour or two."
"Shall we wait?" Scotty asked.
"No need. We can take our floats. Let's get going."
They changed to trunks. Then, since they would not have anyone on the surface to keep track of time or depth, strapped on wrist watches, compasses, and wrist depth gauges. Floats and weight belts were put on, then the boys added small plastic slates and pencils for writing underwater. Knives, masks, snorkels, their favorite guns, fins, and lungs completed their equipment.
"Shall we walk up the beach, or swim?"
"Swim," Rick said promptly. "This stuff is too heavy to carry comfortably."
They launched floats, placed aqualung mouthpieces on top of their masks, and swam parallel to the beach. By using snorkels they avoided the effort of lifting their faces out of water to breathe and conserved the air in the tanks. With effective but effortless leg strokes they moved along rapidly.
As they approached the ship rib that Scotty had found they turned and swam straight out toward the reef, crossed it, then came to a halt.
"Let's tie our floats to something," Rick suggested, and Scotty nodded.
Aqualung mouthpieces replaced the snorkels, and each boy tested his flow of air, checked to be sure his mask was connected to the lung by a safety line, charged his gun, and set his watch. The watches, designed especially for underwater swimming, had an outer dial that could be set to show elapsed diving time.
Rick hooted and pointed down. Scotty nodded and they submerged. Because of their belt weights, and the weight of air in their tanks, they were just heavy enough to sink slowly. After the dive, when the air in the tanks was nearly exhausted, they would weigh about five pounds less and have a slight positive buoyancy that would help them to rise.
They found coral outcroppings and tied their float lines, being careful not to cut their hands. Rick suddenly wished they had brought canvas gloves. Scotty still wore a single rubber one.
Then, with a few strong kicks to overcome their inertia, they started down the face of the reef. It fell off sharply for about forty feet, then more gradually until sand bottom was reached at about ninety feet.
Rick felt the sensation of thrusting his face into a wedge as the pressure increased. He swallowed a couple of times and felt his ears equalize, but his mask was beginning to hurt. He exhaled through his nose and equalized the pressure inside the mask.
There were plenty of fish around now. A grouper saw them coming and ducked into his hole in the coral. A fairly large moray eel, only his head visible, watched their progress. Tiny demoiselles fluttered around them, and a pair of red squirrelfish watched from the shelter of a purple coral fan.
The coral growth was spectacular, with fantastic shapes and colors. Then, as they went deeper, the colors gradually faded to a uniform green. Rick knew from underwater flash photographs that the appearance was deceptive. The colors remained, but the quality of light changed.
Scotty hooted four times, the signal for danger! Rick looked and saw a barracuda hovering near by. He gulped. The fish was easily five feet long. Both boys lifted their spear guns just in case the 'cuda attacked, but the motion alarmed him and he was gone with one powerful flick of his tail.
Rick consulted his wrist depth gauge, holding it close to his face plate. They were at bottom at ninety feet, and the clean sand dropped away at an angle of about thirty degrees. The boys planed downward, a few feet above the sand until Rick's gauge read 120 feet. This was the limit of their dive. Going deeper would mean stopping for decompression on the way up.
He recalled that the waves came into the beach from a slightly northerly direction and motioned to Scotty that they should turn north. Scotty moved out to the limit of visibility, and they swam on a compass heading of north, watching for any sign of a wreck. Now and then a coral shelf extended out from the reef, but they saw nothing that could have been a wreck. Once they swam over a patch of marine growth perhaps twenty feet long and ten wide, and a huge eagle ray lifted from it and glided off like a weird futuristic airplane.
It was quiet, except for the regular chuckle of their exhausts, and the light was subdued and even. It was a world without shadows. Still, Rick thought, there was plenty of light for photography. Next time he would bring his camera.
The watch showed him that over half their allotted time was gone, and he hooted once to Scotty, then reversed course, heading back toward their floats.
They approached the patch where they had seen the ray and Rick paused suddenly. There was an odd shape on the sand near the patch. He flippered over to it and examined it. Scotty joined him. It looked like an oversized mushroom protruding from the sand at an angle.
Rick unsheathed his knife and poked at it. The sharp tip penetrated for a fraction of an inch, then stopped. It was either rock or metal, and judging from the shape, it was unlikely that it was rock. He put his knife under it and pried, and the thing moved in the sand.
Both boys went to work on it, scooping the sand from around it. In a moment they had it clear. It was something like a dumbbell, covered with marine growth where it had been above the sand, but fairly smooth under it.
Rick took his belt slate and scribbled, "Metal."
Scotty nodded. Then both of them turned to look at the patch of marine life.
A distant throb, as though of a boat, caught their attention. They looked up, but the surface was invisible.
It was Tony and Zircon, Rick decided. They probably had returned to the cottage and found the diving equipment missing. They could spot the location where the boys were diving easily enough, first by the floats, then by the bubbles of their exhausts.
Scotty hooted suddenly, four times. Rick turned quickly in time to see a six-foot shark speed past. The tips of the pectoral fins and the second dorsal were darker than the rest of the fish, and Rick identified it as a black-tipped shark. Obviously, the shark was on business of its own, not particularly interested in them. Still, it was curious. The shark was rushing almost straight up.