Up to 60 feet long (roughly the length of a bowling lane) and weighing more than 50 tons, the indomitable megalodon shark, the largest fish that ever lived, tore its way through the whales and dolphins of the world’s oceans for about 13 million years before dying off about 2.6 million years ago. During their reign, megalodons shed their fearsome teeth — up to 7 inches long — to the ocean floor, where they fossilized over following millennia. The remnants of the most forceful bite of any animal in history now lie buried in just a few inches of sand under the warm, clear, Gulf Stream waters that flow northeast past the coast of North Carolina. Though megalodonsnever coexisted with modern humans, their teeth are now costing human lives.
Hardy divers willing to endure long and often rolling boat rides out to the “Meg Ledge” for brief bottom times in depths of more than 100 feet of seawater (fsw) may be rewarded with the recovery of one of these treasured teeth. Imagine the bragging rights of returning to shore with an ancient shark’s tooth that completely fills your hand, and the appeal of pursuing these teeth is understandable. Recent years, however, have yielded fatalities and injuries of divers searching for megalodonteeth, including two fatalities in 2018 off the iconic North Carolina coastline. Nonfatal incidents have included hospitalization for decompression sickness and other injuries and no shortage of unreported close calls.
Divers on boats carrying prehistoric tooth hunters have jokingly used the term “tooth fever” to describe their fellow divers who rush to put on gear, quickly descend the line and begin excavation for teeth as soon as the mate ties off the anchor line. Their excitement is reasonable as divers travel great distances to visit North Carolina and then board an hours-long boat ride to about 30 miles offshore. With precious few minutes of bottom time to find a promising dig site and search for teeth, no one wants to go home with an empty mesh bag after investing the time, money and effort. That singular focus may carry a high cost. Divers and crew alike have observed that feverish tooth hunters may neglect to follow a dive plan, disregard gear checks, leave equipment behind, forget to monitor gauges and ignore the use of the buddy system in their quest.
As with any underwater pursuit, divers must weigh the value of the hunt for teeth against their own health and safety. As part of risk reduction, we must examine factors that contributed to deaths and injuries and use that information to improve safety. We do so not as criticism of those who were injured or who died, but so that some meaning and betterment can be taken from their tragedies.
A review of recent fatality and injury cases of North Carolina coastal divers by members of the U.S. Coast Guard, professional dive instructors and the North Carolina Office of the Chief Medical Examiner identified multiple safety risk factors that all divers should consider, whether hunting for fossilized teeth or pursuing other underwater activities.
Have a Dive Plan
A diver focused on the goal of a dive may neglect the dive itself and with it the protocols for gear preparation and checks. Documented findings revealed divers leaving behind alternate air cylinders on the boat deck, when a backup air source would have meant a lifesaving option for an out-of-air emergency. Rushing to enter the water without proper gear checks increases the risk of an underwater emergency due to gear malfunction or lack of appropriate equipment. Having a well-established dive plan is a critical component of recreational and technical diving taught at all levels of dive certification. Don’t get in the water until you have reviewed your dive plan with your buddy diver(s) and conducted proper gear checks.
- Slow down! Conduct equipment checks, and follow your dive plan. Those teeth have been there for millions of years. They can wait a few more minutes.
Solo Diving
Divers hunting for teeth seem to prefer operating alone as they fan the seafloor or blow it with scooter wash. If a diver experiences an out-of-air emergency while solo diving, there are no nearby divers or resources to assist and provide critical air for survival. Without an alternate air source, an out-of-air situation at more than 100 fsw requires the diver to ditch weights, drop bags of rocks and teeth and make an emergency ascent without additional air. This dangerous scenario increases the risk of drowning, arterial gas embolism and decompression sickness. An added risk for Meg Ledge divers is that they are often heavily weighted to stay on the bottom while searching for teeth.
The Coast Guard recently identified divers at the Meg Ledge often deliberately carrying out solo diving activities without possessing the applicable solo technical dive certifications and experience. Meg Ledge divers often descend to the seafloor and spread out in different directions to search for teeth. The distances may vary, but it is not uncommon to be 30 to 50 feet from the next nearest diver and have no visibility of their location. Using wreck reel lines as breadcrumbs to find their way back to the anchor line, the divers purposefully separated themselves significant distances, abandoning the buddy system they were trained to use and disconnecting their lifeline to the only source of assistance during an underwater emergency. This unsafe practice is common for Meg Ledge divers but contradicts diver certification instruction.
- Keeping a buddy a few feet away won’t prevent you from finding teeth, but it could make the difference between a close call and a fatality.
- Diving with a buddy just makes sense. Even if you don’t worry about your own safety, consider how you would feel if someone in your group was injured on a dive and you could have been there to help.
Diver Propulsion Vehicles
Fanning the seafloor with your hands to uncover prehistoric fossils beneath the sand is both an exciting and tedious activity. Divers often use a diver propulsion vehicle (DPV), or underwater scooter, to save energy and oxygen and increase their range and bottom time. To expedite their productivity during precious bottom time, divers have introduced a more efficient way to excavate sand from the seabed.
Megalodon teeth hunters often use the DPV for a purpose other than its intended design and in a way that may increase the risk of underwater fatalities. After spreading out in different directions alone on the seafloor, some Meg Ledge divers flip their DPV upside down and point the scooter fan blades directly at the ocean floor. The powerful fan wash excavates the sand around them with great proficiency, but it also creates a large plume of fine ocean floor particles and sand that engulfs the diver and causes an extremely low-visibility condition. It can affect the diver’s ability to visually check critical air gauges and dive computer displays and may even cause harm to their life-support equipment. In addition, the low-visibility conditions from DPV blowing prevents buddy divers from monitoring each other. Divers tend to avoid the low visibility created by the DPV and separate themselves further from their buddy, which is a critical risk to assisting a diver in need.
- Use your scooter for scooting. It was not designed for excavating sand, which creates a low-visibility condition that prevents your buddy from monitoring your condition and is an unnecessary risk.
Other Considerations
Whether searching for shark teeth while diving or sending a text message while driving, we all know that being focused on a task takes attention away from monitoring critical information. In the case of Meg Ledge divers, the motivation to find those large, striking teeth has resulted in out-of-air situations and unplanned decompression obligations when divers neglected to check gauges early and often. The most important task you have is to resurface uninjured and alive.
Experienced Meg Ledge divers have fallen victim to assuming that if the gear worked fine for the last dive it will be fine for the next. Outdated computers, poorly maintained buoyancy compensator devices (BCDs), and regulators allowed to go past manufacturer-recommended service intervals can lead to equipment failures that result in injury or death. The Meg Ledge dive is a technical diving activity that attracts recreational divers. Experience and certification for the type of dive conducted is critical to the diver’s preparation and success. The operating depths, low visibility, square dive profile, moderate sustained workload at close to maximum depth for most of the bottom time, lack of topside supervision and distance from a recompression chamber requires conservative measures, training and experience.
Divers searching for megalodon teeth prefer to be heavy on the bottom, which can be dangerous in an emergency, especially an out-of-air situation. A diver with a heavy backplate and steel tanks has no weight to dump to gain buoyancy in an emergency. A heavy diver who does not ditch weights in an out-of-air situation has no way to inflate a BCD. Divers may have heavy bags of teeth, fossils and other items clipped to a BCD and either forget to ditch that bag in an emergency or avoid ditching it, thinking that the situation is still under control.
Lead weights, megalodon teeth and fossils are replaceable. If a controlled swimming ascent is not working, dumping weight and risking an out-of-control ascent is still better than drowning in an out-of-air situation. These weights should be capable of quick release in an emergency.
While we tend to think of experienced divers as being safer, the opposite may be true. Experience, particularly with the same dive or type of dive, is sometimes associated with less focus on gear checks, gauge monitoring and other safety measures. The “been there, done that” attitude reduces risk perception, but even experienced Meg Ledge divers must still do the necessary preparation, checks and gauge monitoring.
Searching the Meg Ledge for teeth may be a very active dive compared to photography or cruising a reef. The act of fanning sand or blowing it with a scooter causes higher air-consumption rates. Besides requiring more frequent gauge monitoring, working dives are shown to be associated with a higher risk of decompression sickness. Working divers have also been observed to skip breathe — take a breath, briefly hold it and then exhale. Besides leading to carbon dioxide retention, the breath-hold from skip breathing also carries a risk of pulmonary barotrauma if done during ascent. While exerting themselves, divers should monitor gauges more than normal, control their breathing and slow down.
Many of these risk factors apply to more than just the Meg Ledge divers of North Carolina. Between Jan. 1, 2017, and April 22, 2019, the Coast Guard investigated 73 recreational diving casualties throughout the country resulting in personal injury or loss of life. Even if you have never been diving off the Carolina coast, you might recognize some of your own risky behaviors. If so, take a moment to consider your own risk reduction as well as that of your fellow divers. No shark tooth, photograph, lobster or fish is worth neglecting the fundamental safety protocols we all learned in our open-water training.
The views expressed here are those of the author and are not to be construed as official or reflecting the views of the commandant or of the U.S. Coast Guard.
Thomas Powell, Josh T. Norris and Craig Nelson, M.D., Associate Chief Medical Examiner in the North Carolina Office of the Chief Medical Examiner, contributed to this article.
Explore More
Learn more about the megalodon teeth found off the N.C. coast in this news report.
© Alert Diver — Q3 2019