I punched in the autopilot and used the paper napkin to pick up the gun and let back its hammer. It didn't smell like it had been fired, and all the visible chambers were loaded. Maybe the victim was an unlucky hunter who was killed before he could get off his first shot. I put the revolver in a drink holder under the console and went back to the routine: steering, thinking, and taking rectal temperatures on schedule.

      It took an hour for the "MS" marker to come into view and another hour to round it and start heading south along the western edge of the Little Bahama Bank. Off to the right, the Gulf Stream water was as blue as the sky above us. And 20 to 40 feet below me, the bottom glided by -- a patch of grass here, a patch of sand there, punctuated by chimney-shaped sponges and brain corals ranging in size from a picnic table to a VW bug. Occasionally I could make out a snapper, a yellowtail or a brightly colored reef fish. My Polaroid sunglasses did such a good job of blocking surface reflection that the water seemed to have no surface at all. It felt like flying over a landscape of green, beige, red, brown and blue hills and valleys which rose gently to our left to meet a silvery horizon.

      The bottom contours were so regular that Rebecca needed few adjustments to our average course of 165 degrees. Here on the edge of the Bank, the Gulf Stream wasn't fighting us more than one knot.

      With little to do but follow Rebecca, I spent the time thinking about the crime we'd discovered. Why does a man go trawling at 2.9 knots at night without fishing line but with night vision goggles and a cocked revolver? Was it a drug deal gone bad? Was he the buyer or the seller? Was the revolver his only armament? Why hadn't he taken a rapid fire weapon? Was he doing the deal alone? Did he have a partner or sidekick? If the sidekick was the one that did it, how had he gotten off the boat? The stern didn't have any davits for hanging a dinghy or inflatable boat behind. My inspection of the front deck didn't reveal any shackles, straps or tie-downs for an inflatable, either. And why would the murderous sidekick take the chance of lining up the shot for the front of the chest when it is so much safer to shoot a guy from behind?

      Well, when the police identified the victim and his boat and started interviewing people, they should be able to test the murderous sidekick theory for us. Correction: They would check it for themselves because Rebecca and I weren't going to get involved.

      The alternate theory would be that the victim was out alone and was attacked by a boat full of bad guys. They pulled up to him, knocked him down with a chest shot and sent one man aboard to deliver the executioner's shot. The fact that they'd chosen to sink the boat with a tight pattern of shots at the waterline said many things about them. Either they were stupid, or they didn't know much about boats, or they were in a big hurry.

      Hell, if I'd wanted to scuttle this yacht and make it look like an accident, I would have laid a wrench on the bilge pump float switch so it couldn't turn on, and I'd loosen the aviation clamp on one of the raw water hoses and pull off the hose. That would take the boat down in 15 minutes. Barracuda and shark would scatter the body parts and nobody would know that a crime was committed.

      I went back to speculating about the victim's intentions until Rebecca asked for another temperature reading for the time of death calculation. That got me wondering whether it would be possible to deduce the time of the attack from how long it took for the yacht to flood to the level we found. The principles were simple -- a race between the leak and the pump. The pump has only two speeds: off and full speed. If the leak were slower than the pump there would have been no problem. The pump would click on when the water rose an inch or two, and would click off when it had pumped it back down. And the water would never rise above the bilge.

      If the leak is faster than the pump, the boat will sink. If the leak is a lot faster, the boat will sink in a short time. If the leak is only a little bit faster, the boat will take a long time to sink.

      I spent some time thinking about how I could use calculus to compute how long the race had been going on. Then I thought up a simple experiment that I could do, once we got the Second Chance to safety.

      While eating the lunch that Rebecca made for me, my thoughts returned to the other calculation I had made:

      We were going to earn $100,000!

      The calculation was easy. This smudge pot had to be worth around $200,000. A salvager who saves a boat from going down can claim 50 percent of its value. Now $100,000 would be a nice chunk of change -- enough to keep this biomedical scientist and his physician fiancée going for a couple of years. Between jobs, as we were, we could use the money. I had given up my job at the U.S. Patent and Trademark Office and Rebecca had given up her fellowship in world health at George Washington University.

      Actually I'd given up the Patent Office job a couple of months earlier and had accepted a research assistant professorship at Bryan Medical School in Miami. After I'd worked hard there to start a career in laboratory research, the effort sort of exploded in my face. But that's another story. After the dust settled, we sailed out of Chesapeake Bay, planning to take a two-month vacation cruising the Bahamas before looking for work in Miami. My long-range goal was to build up a pharmaceutical consulting practice. Rebecca's plan was to find a job in an emergency room or to do family medicine in a small group practice. Her true passion, third world medicine, she would pursue in her spare time.

      My black-haired, green-eyed soul mate called me on Channel 13 for another temperature reading. After giving it to her, I praised her piloting and her corned-beef sandwiches. She reminded me to put sunscreen lotion on my face and neck. I thanked her for thinking of me and keeping me on track.

      I meant it sincerely. That slender, Manhattan-bred lady was the best thing that ever happened to this mid-sized, oversexed New Jersey Italian. Several years ago, she had rescued me from a downward spiral towards the life of a boat bum. She had shown me how to get useful work out of my high-voltage brainstorms. And, in appreciation, I had shown her a kind of love that she'd never experienced before. And now, with Rebecca in her late twenties and with me in my early thirties, we were lifetime partners.

      Once we completed this salvage, our partnership was going to be $100,000 richer.

      Of course big chunks of cheese invariably attract nibblers. It would be a shame to have to spend any of that money on a Bahamian lawyer. But I might need one if Bahamian bureaucracy asserted authority over the yacht. The best way to avoid pests is to leave nothing that will attract them in the first place. I spent some time formulating oral statements that I would make to the Bahamian police and customs officials. I worked them up as a half dozen sound bites that would reveal me as an expert on maritime law who would stoutly defend his rights:

      "Were it not for the dead man on board and the need to bring the crime to the immediate attention of the nearest police authority, we would have taken the salvaged yacht directly to its home port of Miami."

      I practiced laying in a respectful pause and viewing the official with a diffuse gaze.

      "It is, of course, unnecessary to say that the Bahamian Government has no jurisdiction over my salvage claim."

      I practiced waiting him out until he backed down. And I practiced a response if he turned argumentative.

      "Of course, I would be glad to render a written statement to that effect if I were furnished with the name, title and address of the responsible official on the Bahamian side."

      I practiced those sound bites until they rolled off my lips with ease. Eventually I stopped pacing. I sat down and went back to thinking.

      Maybe I didn't really have to deal with Bahamian authority. Palm Beach was only 60 miles to the west. The rubber foam on my patch was fluttering, but it was holding well. The bilge pump was clicking on only once every 10 minutes. The engines were doing fine and the gauges said we had plenty of fuel. We could make the Port of Palm Beach in about 11 hours. We could hand the murder investigation over to the Palm Beach Sheriffs Department. They would investigate the murder professionally.

      Or would Palm Beach complain that my actions had caused an intolerable delay? Would they accuse me of obstructing justice? West End was only four hours away. Maybe International Law actually required us to go to the nearest port with police authority, even if the crime was committed in International Waters.

      Where had the murder taken place, anyway? When we discovered the yacht, it had been coming from southwest by south. That direction took in a slice of the Little Bahama Bank and then the Straits of Florida. I hadn't found any charts on board, but I didn't really need any right now. I knew this part of the Bahamas like the palm of my hand. In fact that was exactly how the Little Bahama Bank looked -- like the palm of my right hand. I held it in front of me, horizontally. My thumb formed the north side of the Bank. Beyond it was the Atlantic Ocean. My little finger formed the Grand Bahama Island which lies on the south side of the Bank. And the rest of my palm and fingers was the Bank, a big expanse of shallow water, six to 18 feet deep. Beyond my fingertips, to the west, were the Straits of Florida and then the Florida coast.

      It wasn't a bad map, my flattened hand. The place where we'd found the Second Chance was half an inch north of the last joint of my index finger. At the present moment, we were at the tip of my longest finger, at the western edge of the Bank. And at the tip of my little finger was our destination, West End, so named because it was on the western tip of Grand Bahama Island. The Island is long and narrow. On my improvised map it took in the little finger and the edge of the hand that delivers a karate chop.

      I stared at my improvised map for a long time, trying to figure out where the Second Chance had been eight hours before we found it. If it had been traveling straight and steady all that time, it would have started out between 16 and 23 nautical miles southwest by south of where we found it. That would be on the pad of my longest finger. That would put the murder on the Little Bahama Bank, inside Bahamian jurisdiction.

      A problem with that simple calculation was that it had the yacht moving over a lot of shallow water -- sand bores and fish muds -- where it should have run aground. Another problem with that straight-line calculation was that it didn't take into account the influence of wind, tides and ocean currents. The night before, we'd had a strong northwesterly wind that weakened and shifted to northerly before dawn. The wind would have been pushing the yacht southeastward, bending its course. The murder could have taken place in the Straits of Florida.

      Staring at my hand again, I factored in the currents this time. In the middle of the Straits of Florida, the Gulf Stream flows northward at about four knots. Along the edge of Little Bahama Bank it moves at only one knot. Where the Gulf Stream passes the northern edge of the Little Bahama Bank there would probably be eddy currents. Taking all this into account, I got a much different result: The murder was probably committed in the Gulf Stream, 10 to 20 miles due west of West End.

      I was proud of having done these vector calculations in my head. But I would have been happier if the result had been 13 to 23 miles west of West End. That would have put the murder completely outside of Bahamian jurisdiction. I was about to launch into a new set of calculations to see if the result could be moved a few miles westward when I stopped myself:

      No, Ben, you can't do that. A scientist lives by a code of intellectual honesty. And the scarcer the facts and the more complicated the calculations, the more important it is that you keep to that code. West End is now only 30 miles away and you must lose no time in turning the crime over to police authority. Do your good citizen's duty.

      Basta! Enough! That's what my Italian grandfather would have said.

      My eyes returned to my hand. It was shaking. And while wondering why, I came up with an uncomfortable thought: Had the murderer operated out of West End? What would the murderer think when he saw me pulling in with the resurrected Second Chance?

      I scanned the horizon. There was one sport fisherman about 10 miles to the west. And West End's water tower was now emerging before me like the tip of a ballpoint pen held at arm's length. It was still far away.

      As the day wore on, I thought more about the crime. Eventually I came up with an idea for a new calculation. I punched in the autopilot and went below to get a small drill bit. Probing with it carefully in the chest wound, I found that the hole pointed upwards at an angle of around 30 degrees. I took another temperature reading for Rebecca, then went back to the flybridge. Before calling her, I took another look at the radar display. It was showing two big blotches straight ahead. The outer one was the West End water tower. The other was the Diogenes. And the rest of the screen was pocked with false returns. I turned the unit off.

      I got Rebecca on Channel 13 and told her about my calculations and my plans for dealing with Bahamian authorities. And I said that the murderer would feel threatened by us. "We're going to keep a low profile when we arrive."

      "I agree," Rebecca said.

      "We won't tell the people about our temperature measurements, the vessel's course, or my calculations. We'll save that for the police."

      "Roger that."

      "We'll tell the police about our qualifications. They'll need to know that for their investigation. But we shouldn't let people know that you're a physician and I'm a scientist. The less they know about that, the better."

      "I agree, but if we give them a complete lie then we'll seem all the more suspicious if they find out."

      "I agree. I'll say I'm a patent evaluator."

      "Good. They may not ask me, but if they do I'll say I'm a world health policy evaluator."

      "And since we're coming into radio range for West End, even for one watt, we won't be able to talk like this any more."

      "Roger. But keep calling in the temperature readings as long as you can."

      Rebecca had never been to West End. I had sailed into it once, a couple of years before I'd met her. I told her about the shoals and currents around the channel leading into the West End marina and how I wanted us to maneuver, once we reached its mouth.

      "When are you going to tell them we're coming, Ben?"

      "When we are abreast of West End."

      "It seems clear to me, Ben."

      "I'm going in there as the salvage master of the Second Chance, which I am returning to its home port in Miami. Officially the only reason I am stopping at West End is to turn the body over to the nearest police authority."

      "I read you loud and clear, Captain."

      "Great. From now on we monitor Channel Sixteen. I'm over and out on Thirteen."

      "Over and out, Ben."

      Over the next hour or so, the West End water tower grew to the size of a pen tip, to a thimble, to a red and white mushroom. And it was all too soon that we came abreast of it. At 3:17 p.m., I threw over the wheel. The low November sun moved from my shoulder to my back. Although we had been in transit over seven hours, I hadn't thought enough about the salvage work at the dock and dealing with the people at the marina. Well, I would just improvise. That's how I do my best work, anyway. I picked up the hand-held, now set for Channel Sixteen, and squeezed down.

      "Ben Candidi calling West End Marina." I repeated it three times, paused, and repeated it three more times.

      "West End Marina to Candidi. Please switch to Channel Twenty-Four." The voice was Bahamian, female and businesslike.

      "Negative. Please stay on Sixteen and listen carefully. This is an emergency. I am two miles west of you and am approaching. I am at the helm of the sport fisherman yacht, the Second Chance, which I discovered and salvaged in International Waters several minutes before it would have sunk. I am requesting a temporary berth."

      "You are salvaging the Second Chance." She said it as a statement but meant it as a question. And there was no question that she knew the vessel.

      "Affirmative. And I will need to be directed to the shallowest berth you have. I will need men and four dock lines. Additionally I am requesting that you call the Royal Bahamas Police Force and have them dispatch a homicide detective. When I boarded the vessel, I found a man aboard, dead from gunshot wounds."

      "I copy both requests." She said it professionally, with not a trace of excitement.

      "One further request. I will be followed in by the thirty-six foot sailing vessel, the Diogenes, captained by my partner, Rebecca Levis. Please have someone give her directions to the deepest berth you have, and give her help with docking."

      To complete the story, I told the marina manager that we had sailed here directly from the Chesapeake Bay.

      My message was received by many people. There were a lot of three-second announcements of boat names and channel numbers -- listeners announcing to their buddies that they were ready to talk on other channels about what they had just heard.

      Rebecca dropped behind as I lined up for the channel. To the right was a rocky seawall; to the left was a large expanse of flats where the water was knee-deep. Rebecca was following about 300 yards behind. For the last minute of approach to the channel, I concentrated on depth and currents. Then I squeezed down.

      "Candidi to Diogenes. You'll be okay. You will have at least seven feet of water. In the channel, watch for a left-going, two-knot cross-current. I'm having to steer against it by ten degrees."

      "I copy that, Candidi. I don't want to end up like the boat to port."

      A glance to the left confirmed what she was talking about -- the careened, stranded and sun-bleached hull of a full-keeled sailing yacht. The wreck stood in front of a small mangrove island, 400 yards up the flats. Straight ahead was another distraction -- a couple of bikini girls on Waverunners, buzzing around in the channel. They should have stayed away and hung to the side, like the dark-haired man with the yellow Waverunner. He slid in close enough for me to see the tattoo on his shoulder, but he didn't get in the way.

      I moved through the channel past the entrance to the modest-sized "commercial harbor." The only sign of commercial activity there was a couple of stacks of pallets. The yacht harbor was the second right. I decreased the revs while closing on the buoy that marked the end of the channel, then executed a sharp right into the marina channel. Although I had been here many years before, I was still amazed at the depth of the cut and the steepness of the coral banks on either side. A row of Australian pines towered on either side. The fuel dock was 100 yards ahead on the right, where the channel opened up into the marina basin.

      The marina basin was as I had remembered. It was rectangular, with docks on the seawalls to both left and right side, and with one long wooden dock projecting toward me, dividing the basin and creating two water lanes from which to choose. All the slips were laid out perpendicular to the docks. Quarters were close.

      The attendant at the fuel dock gave me hand signals toward the right lane. This required a sharp turn to the right and then to the left to get around a big trawler tied up at the end of the center dock.

      Although less than half of the marina's three dozen slips were occupied, it seemed horribly cramped -- like a campground that specializes in recreational vehicles. As I completed my turn and my open cockpit area passed the trawler's stern, I heard the first comment: "Oh, God. They killed him." The words were spoken in a New York voice by an old guy sitting at the upper steering station of the trawler.

      Obviously our sheet did not hide the outlines of the human body.

      Straight ahead, at the end of the lane, was a bare seawall and the marina office. Standing at the edge, a well-dressed Island woman was motioning me to come forward.

      On the next boat to my left -- a large Hatteras -- a pretty blond-headed woman was waving to get my attention. She gestured to the end of the lane, where I was heading. "Steve's slip is over there," she yelled, with Southern accented concern.

      Obviously the Island woman was the marina manager. She gestured for me to take the final slip on the right. Like all the slips along the west wall of the basin, it consisted of a narrow dock jutting out from the seawall on one side and two poles to define its other side. Two local guys were standing on that last dock, holding ropes for me. Getting into that slip required a sharp turn to the right in close quarters. As I counter-rotated the props, I sensed the apprehension of my soon-to-be next door neighbor standing on his mid-size Bayliner. Meanwhile, my across-the-lane neighbor was standing on the bow of his large Bertram with a boat pole in hand like he was ready to fend me off, if necessary. He was middle-aged and wore his gray hair in a Caesar cut. As my boat slowly rotated on its axis and my transom turned towards him, he peered down on it as if mesmerized. But he snapped out of it as soon as I completed the maneuver and began to inch forward into the space between the dock and the two pilings. He jumped off his boat and onto the large dock. He ran along the seawall, past the well-dressed marina manager and towards my dock.

      The two dockhands were standing by, ready to throw ropes.

      "Don't anybody come aboard," I yelled to them. "This is a crime scene." Caesar Haircut stood at the edge of the seawall, ready to push back my bow if I didn't stop in time.

      A couple of seconds with the props in reverse brought the boat to a halt in the right place. What a relief to put the throttle levers in neutral! I scrambled below to secure two starboard dock lines. The guys handed me two more lines to throw over the pilings on the other side. After securing those lines, I repeated my keep-off-the-boat order on my hand-held radio. It was eerie, hearing my voice from several directions in the marina. It seemed like everybody was tuned into Channel 16 with the volume up high.

      Caesar Haircut had stationed himself at the base of the narrow dock that I shared with the Bayliner. He kept himself busy holding back onlookers.

      With regal bearing, the marina manager worked her way through the gathering crowd and addressed me. "The police are on their way." Her voice was the same as on the radio. "Is there anything else I can do?"

      "Yes, I would like to hire these two men," I answered, making eye contact with the older of the two dockhands. "Sir, I'm ready to pay you and your buddy fifteen dollars an hour, starting right now."

      "No problem," he said. "My name is Edgar." He was middle-aged, healthy, and seemed to have enough muscle for the job.

      "Great. My name is Ben. I saw a stack of pallets on the dock of the commercial harbor. Bring them here. I need to get them under the boat to stabilize it."

      "No problem." He spoke with an Island accent, but with the hard undertones you might expect from a foreman.

      "And if you can find some rocks to weight the pallets down, that would be good, too."

      Edgar and his younger buddy went off in the direction of the pallets and the dockmistress went off in the direction of her office. It was time to thank the paunchy middle-aged guy with the Caesar haircut and the Bertram. "Thanks for the help with crowd control."

      He waved a big hand and a pudgy forearm in a quarter arc. "Think nothing of it. My name's Wade. Wade Daniels."

      It was a stroke of luck that he'd stepped in because a crowd was growing. They were a fifty-fifty mix of boat owners and Islanders, fanned out along the bend in the seawall in front of the marina office. From ten yards, they all had an unobstructed view of the Second Chance's damaged port side but couldn't see the white-shrouded dead man. However, a lot of people had crowded the top deck and bow of Wade Daniels' Bertram, and they were looking down on my cockpit, seeing everything. There was no time to think about public relations. I had a salvage job to complete.

      Looking over the port rail, I was pleased to see the rubber foam was still bulging through the hand-sized hole in the hull, just below the waterline. The depth sounder said there were three feet of water under the hull. A glance at the barnacle-encrusted pilings holding up the dock told me that the tide was rising and had another foot to go before it crested. That would probably take two more hours. Sunset would come in about two hours, with darkness shortly after that.

      Edgar and his buddy deposited a couple of pallets on the seawall and went off to get more.

      While checking the rope locker, I looked up to see Rebecca coming up the dock. With no visible change in her bouncy stride, she negotiated the four-foot drop from the dock to the yacht's cockpit, throwing in a couple of steps along starboard rail to ease the transition. She threw an arm over my shoulder, leaned into me for a kiss, and spoke to me in a semi-whisper.

      "Everyone was so focused on you, Ben, that there was nobody to help me dock the boat. But don't worry, I didn't scrape anything."

      "You did great." I kissed her on the cheek.

      Continuing in a soft voice, she said, "I agree with you about keeping it low key, but I should take a look at the body to assess blood pooling."

      "Right," I said.

      She peeked under the sheet to examine the corpse.

      I knelt beside her. "And you can sign off on my observations."