I write this with great pause out of respect for those who have lost friends and loved ones this diving season, though it goes without saying that this summer season has been a particularly perilous one and my hope for all is that we can find something positive from these local events.
Just a few weeks ago, I wrapped up one of my extended range forays from Ft. Wetheril to surface and see an ambulance in the parking lot. By the time I regrouped and made it to my truck, they were leaving, and I wasn’t able to gather any facts about the incident. Around the same time, a local working diver suffered a fatal incident while working in Newport Harbor. Just last week news spread about another fatality in Jamestown. And finally, yesterday, the local news announced a search for a diver who went missing while diving the Andrea Doria off of Nantucket.
On all of the former, I don’t have enough information to comment specifically, but do want to take the opportunity to be an advocate for safety. As I’ve said before, you can drown in a bowl of soup if you aren’t careful enough, and it is often this complacency that gets people in trouble – perhaps more often than actual danger or circumstance. Plan your dive, dive your plan, and remember the basics – stay healthy, train to dive when you aren’t diving, maintain your equipment, and always STOP, THINK, ACT.
On the latter, the Andrea Doria is notorious for related incidents. A few years ago, I was interviewed about an incident on the Doria for NBC10. My feelings are the same today – that being no matter the level of preparations, at some point we have to evaluate risk, and stack that risk against the purpose of the mission. I find as much enjoyment in deep diving as the next, but often question the motives of many pursuing these big dives. In the recent incident of the missing diver, with mention of the diver making it to the 20 foot decompression stop, the situation illustrates what I believe to be among the most overlooked and critical phases of deep dives.
The human transition from the surface to one atmosphere, and then one atmosphere to the surface is where we are subject to the most radical change in pressure, and where many problems can arise. Current can be swift, waves overhead can cause pulses in pressure that can result in over-expansion injuries, lengthy stays mean exposure to these elements as well as being a sitting duck for transient predators, and sitting still just invites hypothermia to set in. Physiologically, this pressure transition is also where we have to be most careful during mixed-gas dives (required for depths such as the Doria). Too little oxygen, and the diver can go hypoxic, essentially blacking out. Too much oxygen at teh end of the dive can result in oxygen toxicity. If diving a rebreather, pushing the carbon dioxide scrubber after a long dive to breakthrough can be cause for hypercapnea. These three H’s – hypoxia, hyperoxia, and hypercapnia – all have a degree of voodoo science within them given the wide range of day to day variability from person to person. We cannot make presumptions about the current incident, but we should certainly take the opportunity to put more thought into management of these shallow transitional dive phases. With extended range diving, I tell students that the surface is not an option, and that means preparing for spending potentially a long time within these zones.
Diving has inherent risks, as the activity challenges our very basic human need of breathing. For many, the enjoyment of the activity comes with finding innovative ways to overcome this challenge and improve the human experience underwater. This is both an art and science, and be treated as the priority field of study that it deserves, because it does, as our lives truly depend on it.
Be safe out there.