Complete darkness. Deep water. Caves. Confined spaces. Skeletons. Some common primal human fears to be sure. Taken together, they made for the most memorable dive of my recent scuba diving trip to the islands of Mabul, Kapalai, and Sipadan off the coast of Malaysian Borneo.
I saw the sign as soon as my wife and I sat down for orientation after our 12 hour journey from Taipei to Mabul Island – Tour the Sipadan Turtle Tomb. The Turtle Tomb is an ocean cave where one can find the remains of unfortunate turtles that became lost and perished in the darkness over the years. I vaguely remembered hearing of the Turtle Tomb and was immediately intrigued. We thought about it for a few days since it is a real cave dive and presents additional risks, but the lure of such a unique diving experience was impossible to resist.
The night before our dive, we sat down after dinner with our guide Ronny to watch a short orientation video. We reviewed the dive plan, including the cave layout and special safety procedures. The two main additional precautions are use of a guide line and an additional air supply. The guide line is a rope attached to the cave entrance and unreeled as one swims into the cave. If visibility is degraded, divers can follow the line out of the cave to safety. We each carried an additional air tank since surfacing in out of air emergency is not possible in a cave. Lastly , we also made sure to have several light sources.
We set off at 5am on the early boat for a private dive under a beautiful sunrise. After entering the water I noticed my air tank was leaking a bit from the o-ring area. This is pretty common on rental tanks that get a ton of use, but this was not the dive to take chances. So I got to practice removing and replacing my gear on the surface as my tank was swapped for a new one.
The open water access to the cave system is in about 60 feet of water in the wall just off Sipadan Island. After dropping our side-mounted spare tanks and fixing the line just outside the cave mouth, we set off into the darkness. Access to the cave proper is through a 120 foot tunnel wide enough for divers swimming single file. The visibility inside the cave was so crystal clear that photographs could easily be mistaken for a snow covered mountain. We preserved the perfect visibility through careful buoyancy control and modified finning to avoid stirring up the silty bottom.
The first feature we explored was a long tall tunnel that reminded me of a cathedral, with a tiny window at the far end providing the only emergency exit to the open water – so small that a diver would have to remove their gear to fit through the opening (good thing I just practiced that!). All around the cave walls were light colored on higher portion and dark on the lower. As we slowly navigated around the main part of the cave, we came upon skeletons in various states of decomposition, some looking quite old and bleached, and other more recent specimens still retaining outer shell coloration. In one spot, an air bubble accumulated at the ceiling creating a dry spot you could stick your head in. I didn’t, considering the air would probably be rather foul. Before we completely exited to open water, we took a few minutes to stop, turn off our lights and contemplate the blue glow from the outside sunlight water. Checking my dive computer, I was surprised to note an 83 minute bottom time, making this dive not only the most interesting one of the trip, but also the longest.