CHAPTER XVI
The Deadly Spring Gun
The storm blew itself out by noon of the following day, leaving anovercast sky and heavy swells. An inspection with the binoculars showedthat all was quiet at the frogmen's house. Their boat was tied to thepier.
"They probably recovered the brass ball during the night," Rickobserved, "or perhaps early this morning."
"The question is," Scotty remarked, "did they take the gadget to theoctopus cave?"
Tony joined them on the porch in time to hear Scotty's query. "I canshed some light on that. It happens that I woke up at dawn and lookedout to see how the weather was behaving. The frogmen were anchored offthe eastern reef in the same place. We can assume that they picked upthe brass ball and put it back in the cave near the wreck."
Rick rubbed his hand over his short hair in a gesture of bewilderment."But what's their game? What do they get from the brass ball?"
"I rather imagine Steve Ames would like to know the same thing. If youboys have no objection, I think I'll spend the afternoon at my midden.What are you planning?"
Rick looked at Scotty. "Dive at the wreck?"
"Sure. Frogmen or no frogmen, there's still a golden statue of St.Francis somewhere down there."
After lunch the boys checked their equipment, being particularly carefulbecause they had not rinsed out the regulators with fresh water afterevery dive. Their small supply of water, coupled with the odd hours atwhich the equipment had been used, was the reason. They took a littlewater from their supply and used it to clean the regulators. The rest ofthe equipment would just have to wait.
Tony departed for his Indian midden, tools slung over his shoulder. Theboys started the compressor to fill the tanks used the previous night,then untied the _Water Witch_ and headed for the diving area. Scottyscanned the frogmen's house through the glasses, but saw nothing ofinterest.
They anchored just outside the reef and looked for their buoy. It wasgone, probably torn away by the storm.
"We can find the wreck again," Rick said. "No trouble. I could find myway around here in the dark." He grinned. "I have!"
"Shall we take a look in the octopus cave too?"
"A quick one. I doubt that we'd see more than we saw last night. Our jobnow is finding out what kind of information the frogmen get. And I don'tknow how we'll do that."
"Wait for a break," Scotty replied. "Come on. Let's get into the water."
It was cold. The storm had blown in colder water from the open sea. Rickfelt goose flesh and wished they had brought along midseason suits.
The water was murky, too, because of the sand and silt stirred up by thestorm. The murkiness started about twenty feet below the surface. Notuntil they were over fifty feet down did the water clear again. Thelight was reduced somewhat by the murk, but visibility was good. Rickhad brought his camera to take motion pictures around the wreck. Therewould be enough light.
Scotty carried the big jet spear gun. It was powerful enough to spearsharks or big barracuda, just in case the frogmen decided to be"mischievous" again.
Rick led the way to the octopus cave, glancing up now and then to makesure they were alone in the water. The little octopus was in his usualposition on the ledge.
Scotty, spear gun extended, swam right into the cave. Rick followed,holding the camera tightly to his chest to keep it from scraping on thecoral. Scotty had his flashlight going, so Rick didn't bother with hisown.
The cave was just about large enough for both of them. It was a typicalcoral formation, not much different from the reef outside, except thatthe brass ball was in the center of the rough floor.
The boys examined the cave thoroughly and saw nothing of interest. Rickpushed at Scotty's shoulder and swam out again. Scotty followed. Theoctopus watched them go.
The wreck of the _Maiden Hand_ was just as they had left it, and thegrouper was back in his comfortable cabin. He departed at high speed asthe boys appeared. They had agreed to start work aft of the captain'scabin, and the wrecking bars were carried under their tank harnesses forthe purpose. Both were convinced that there was nothing more to be foundin the cabin, although the possibility remained that false boards in thefloor or walls might conceal the statue.
Rick tied his camera to a projection, then took his wrecking bar andlooked for a place to start. Scotty pointed to a place where there wereboards aft of the cabin they had already uncovered, and they started towork.
By the time they had pried off the first few boards it was time tosurface. They went topside and changed tanks, then rested for half anhour. There was no sign of activity at the frogmen's house, nor couldthey see Tony at work on his midden, since the location was hidden bypalms.
Rick said thoughtfully, "The brass ball might be some kind of signalingdevice."
"What kind of signals?"
He didn't know the answer to that. "Anyway, since it's underwater, if itsends out anything it must be sound impulses. Otherwise we wouldn't hearit wail. And what good is sound if not for signals?" added Rick.
"Sonar," Scotty reminded.
The boys were familiar with sonar because of the Spindrift work on theSubmobile. Very high frequency sound impulses were sent out, and theechoes were timed or used in other ways. It was the way in which bottomtracings were made by surface craft, and the way in which Navy shipsdetected submarines. It could be used for locating schools of fish.
"It could be sonar of some kind," Rick agreed. "But what good would itdo anyone to stick a sonar device on an island like this?"
And there speculation stopped again, the question still unanswered.
They dove to the wreck and continued the hard labor of taking the aftend of the ship apart. When they finally got the new area cleared ofrotted boards and timbers it was only to find a cabin already filledwith sand.
Rick borrowed the spear from Scotty's gun and thrust it down into thesand. It slid in easily, meeting no obstruction. He probed with it butfound nothing except more sand.
Discouraged, he wrote on his belt slate, "Mybe no bottm. Flr of cbn mybe gne."
Scotty nodded. He lifted his hands in a gesture of inquiry. Now what?
Rick thought about it for a moment. Tony had been right! They probablywould have to remove every board in sight, carrying the ship away pieceby piece. But then what? There was the distinct possibility that thestatue was somewhere under sand, and they had no way of removing thesand to see.
It was apparent that most of the ship was under the sand--if theremainder of the ship was still intact. But Rick couldn't escape thefeeling that Captain Campion would have kept the statue close to him.And that meant in the aft part of the ship, the part that was exposed.
Scotty hooted twice, pointing at his watch. It was time to surface. Thenext dive would be their last for the day.
On the surface, Rick sounded discouraged as he said, "The cabin weuncovered might not even have a deck. There may be nothing but a mile ofsand under it. And there isn't much of the aft part of the ship left toexplore, either. I guess tomorrow we can plan to take the captain'scabin apart board by board."
"We'll need Tony and Zircon for hard labor like that," Scotty answered."Notice how quickly you get tired down there? Also, we use air a lotfaster when we work."
"Let's just sort of make a survey this time," Rick suggested. "We canprobe for any cracks we might have missed, and I'll take some over-allshots of the wreck. Then we'll call it a day."
They followed Rick's plan. He took pictures of Scotty, with wreckingbar, prying at likely places in the exposed part of the ship. But Scottyuncovered nothing of interest. In one place his prying disturbed anothermoray, who demonstrated his anger at the intruders by trying to fastenhis needle teeth in the wrecking bar.
A metallic clang caused them to lose interest in the eel suddenly. Theylooked at each other, then turned and swam toward the apparent directionof the sound. At that moment a distant wail struck their ears.
The brass ball!
Rick wondered. He had heard no boat
noise. The brass ball must beoperating automatically. He hooted for Scotty's attention, then pointedtoward the cave.
Scotty checked his spear gun and motioned for Rick to lead. Rick pushedhis camera in front of him and made his fins move rapidly. There mightbe some outward sign when the ball sounded, something that would tellthem a little about its mechanism or purpose.
As the cave came in view he coasted, looking upward. The murky layerprevented his seeing very far, but there was no one in sight. He letinertia carry him toward the cave, then swung upright in the water as hesaw that the octopus had moved a little distance from the cave mouth.
Instinctively Rick knew that something was wrong, but it was too late toget out of harm's way.
A frogman emerged from the cave, spring-type spear gun pointed directlytoward them. The frogman held the brass instrument in his free hand.
Even as Rick hooted a warning, the frogman fired!
His spear lanced through the water directly at Scotty!