Lost on the Seamount

by Howard Hall

Bob photographs a manta  ©Howard Hall

  It has come to my attention that many of my readers especially enjoy stories that describe sudden, inexplicable drops in IQ on my part. These temporary lapses into stupidity seem especially popular with those readers who dive rebreathers. Perhaps this is because they hope to learn something from my experience. Well, here is another episode from the “Howard’s Stupid Blunders” file.

    Rebreathers are becoming increasingly popular with technical divers these days and so I tried to recall something stupid I’ve done while diving with rebreathers. The effort only took a few nanoseconds. Now you’re probably thinking that if you had a complicated, electronically controlled, potentially lethal life support system on your back, you would be extremely careful; that you would probably never do anything carelessly stupid. And if you have never jumped into the ocean with you air turned off or without you fins or without your weight belt, you might be right. But most people are capable of absolutely brilliant moments of hopeless stupidity. Hell, I once watched Stan Waterman himself try to jump off a boat to enter a submerged shark cage having neglected to don his scuba tank! If you have even once jumped in without your fins or weight belt, then after a few hundred hours on a rebreather you will be quite capable of jumping in with your rebreather turned off or any number of other easily avoided acts of life-threatening stupidity. So try to at least entertain the possibility that the following story could have happened to anyone.

    In 1991, Bob Cranston and I spent two weeks diving on the Marisula Seamount (also known as El Bajo) in the Sea of Cortez while making a film called Shadows in a Desert Sea. It was our first experience with rebreathers. We had leased a pair of Mark 15.5 units from Biomarine, the company that built the Mark 15 for the US Navy. Our plan was to take advantage of the bubble-free nature of the closed-circuit rebreather to film schools of hammerhead sharks.

    Each morning Bob and I would begin our dive where the vessel, Ambar III, lay at anchor on the summit of the Seamount. We would drop down to the top of the Seamount at sixty feet, check our gauges and then follow a compass course due north to the edge of the drop off and then cast ourselves off. At the base of the wall we would reach a sandy plain which we would cross while following our compass and maintaining a depth of 110 feet. After a few minutes we would encounter a ridge of rock which we would follow northwest. Fifteen minutes later and at a depth of about 120 feet, we would reach the end of the ridge where we found a small patch of sand. This sandy area, which was about ten feet across, was surrounded by reef that dropped away to deeper water on three sides. This was the spot Bob and I consistently found hammerhead schools.

    Now anyone with more than half a pinch of chicken brains would have taken a buoy out to the spot and marked it. Unfortunately, when Bob and I combined our mental capacities, we came up short. Besides, navigating to and from this spot had been relatively easy and, more importantly, it had been fun. Each morning I looked forward to the swim out and back. It quickly became a routine and we both became confident in our ability to find our way back to the Seamount and the Ambar’s anchor chain.

    Of course, getting lost is seldom a big problem for most divers. If in doubt, sport divers just swim to the surface and check their bearings. But as the days went on and our confidence grew, Bob and I got in the habit of accumulating prodigious amounts of decompression time. Since strong currents frequently swept the Seamount, this decompression could only be accomplished while hanging on a line. Nearest dry land was more than eight miles away. If Bob and I attempted open water decompression, we would be half way to nowhere when we finally surfaced. Of course, today a properly equipped technical diver would simply send up a buoy for a chase boat to see and follow. Unfortunately, the crew of the Ambar were under the impression that we knew what we were doing and so never bothered to watch for our buoy. This was reasonable since in 1991, no one I knew had ever thought of taking an inflatable buoy down to hang on while decompressing – including Bob and me.

Hammerheads over the seamount ©Howard Hall

   One of the potentially frightening advantages to our closed-circuit systems is almost unlimited life support capacity. The 15.5 is capable of sustaining a diver for more than twelve hours on a single dive. This capacity often produced a rather cavalier attitude toward no-decompression limits. This attitude became especially problematic when the hammerheads surrounded our little sand patch like flocks of bats circling a cave entrance. We were often loath to leave before every frame had been exposed on both film cameras and still cameras.

    Our little problem occurred during the second week of our expedition. We were having an absolutely great morning. After reaching our sandy patch at the end of the ridge, we only waited ten or fifteen minutes before a school of hammerheads approached and began circling overhead. The school spiraled above us for more than a half an hour. When the hammerheads finally left, I checked my Orca Edge dive computer (nitrox computers were not available in 1991 much less constant pp02 computers) and discovered I had built up over thirty minutes of decompression time beginning with a twenty-foot stop. No problem, we could stay down here all day.

   Instead of heading back to the Seamount, we decided to move off across the bottom to another ridge we saw a short distance away. We crossed the sand at 140 feet and then ascended the next ridge to 120 feet. We immediately saw a school of hammerheads passing over another ridge even further away.

    After reaching this next ridge, we quickly shot out the rest of our film as hammerheads passed close to the reef all around us. Then, our film supply expended, we checked our gauges and prepared to return to the Seamount. The first thing I noticed was my computer signaling a thirty-foot decompression stop and a total decompression time of more than forty-five minutes.

    Maintaining a depth of 120 feet, Bob and I swam back to the ridge with the small sand patch. Unfortunately, when we got there the sand patch was gone! How could that be? We swam back and forth over the ridge but found no sand patch. I felt like I was in the Twilight Zone! Without finding our sand patch, we had no waypoint from which to navigate back to the Seamount. Without finding the Seamount, we had no way of decompressing without being swept away by the current. I looked at Bob and raised my arms in question. He shrugged and shook his head. I couldn’t believe it. Hadn’t he been paying attention?

    Obviously, we were on the wrong ridge. We swam to the next ridge in sight. Not only was there no sand patch, but the top of the ridge was 130 feet. We were wandering into deeper water! Somehow, we had become completely turned around.

   We decided we would have to make a stab at navigating directly back to the Seamount. It must lie somewhere almost due south of our position. Hell, it’s big as a house. How could we miss it? I pointed to my compass and pointed to Bob. “You navigate,” I suggested. Bob shook his head and shrugged his shoulders.

   I couldn’t believe it! “What do you mean you don’t know which way to go,” I motioned to Bob, getting angrier with myself by the second. “Can’t you tell I’m completely lost? Get us the hell out of here!” I looked at my computer and held it up for him to see. Over one hour of decompression!

    Bob made his best guess at our course and began leading the way. But as we began swimming over patch reefs at 140 feet, I realized he was completely clueless. When it became obvious that his course was leading us into progressively deeper water, he stopped and shrugged again. I felt like punching him in the nose. Our gesturing became so animated that we looked like two of the Three Stooges having and argument underwater. By now the Seamount could be anywhere. I pointed in several directions and raised my arms to ask, “Where do you think it is?” By now I had absolutely no idea and I needed a suggestion. Bob just shrugged again. We were screwed!

    We started moving back in the direction we had come. But frankly, by then I wasn’t even sure what direction that was. How could we have misplaced a rock the size of a really large house? Indeed, this was the Twilight Zone. We couldn’t find our way back and we couldn’t go up. We could probably swim around down here for another ten or eleven hours but by then we’d be looking at about a month of decompression and we’d probably wind up fifty miles from nowhere. I was beginning to feel as helpless as an airline passenger who has just noticed that the wings have fallen off.

    Eventually, Bob and I got a break from the most unlikely of sources. We heard an outboard motor and looked up in time to see an inflatable boat moving across the surface. Chances were that the boat was either traveling to or from the Ambar. We set our compass for the direction the inflatable was going and fifteen minutes later we were thankfully hanging on the anchor chain at forty feet beginning over two hours of decompression. The feel of that anchor chain was one of the most comforting tactile sensations of my life.

    I mentioned at the beginning of the story that I would write about something really stupid I had done, and I’m coming to that. Oh, you may be thinking, “What the heck was that about if it wasn’t about the dumbest dive ever made?” Well, easy for you to say. Frankly, I consider the incident forgivably stupid, not hopelessly, pathetically stupid. Hopelessly, pathetically stupid happened the next day.

    After Bob and I calmed ourselves over a few Coronas on the stern of the Ambar, we still couldn’t believe what had happened to us. How could we have gotten so terribly lost? How could we have missed a rock the size of an office building? After all, we had been navigating to and from that sandy patch for nearly ten days. It was a mystery. It was a fluke. It could never happen again. It didn’t happen again until the next day.

    The next morning we went out and repeated the entire miserable experience again, becoming as hopelessly lost as the day before. I swam around for nearly a half-hour completely lost while calling myself idiot preceded by a colorful combination of unprintable adjectives. Once again we found our way back through pure dumb luck.
The following day we put a buoy on the spot. Duh!