On June 30, Alexey Molchanov broke the world record for deepest free dive with a mono fin. He did it in Villefranche-sur-Mer, France, and he dove on a single breath to an incredible 436 feet deep.
Free-diving is a wild sport. I have a few friends who do it, and I’ve dabbled a bit myself. One in particular (hey, Rory) told me once between drags of a cigarette that it’s mostly a matter of self-control. “Everyone thinks they need air,” he said, “but you’ve got way longer than you think.” Rory’s a different breed, though, and despite his free-diving accolades, I’d wager most free-divers stay away from smoking.
While it is certainly true that you have more time than you think, professional free-divers train incredibly hard. It’s a very simple thing: if you hold your breath and go under water, you’re free-diving. But when you hit different depths, your body does weird things. See, every single action you take require oxygen. When those actions are done, the waste product is CO2. Breathe in, get fresh oxygen for your blood. Breathe out, expel the waste product.
But when you hold your breath, your oxygen levels decrease and your CO2 levels increase. Once the oxygen levels get too low, you simply black out because you don’t have the necessary stuff to keep everything working. On land, of course, you’ll likely just wake up when you get more oxygen. But in the water? We don’t come equipped with gills, so if you’re not diving with a buddy… well, let’s just say you should always dive with a buddy.
One of the weird things about our super-complicated brain is that it’s actually pretty bad at telling you that you need oxygen. What it’s good at, however, is responding to increasing levels of CO2, which effectively has the same end result. You feel a great need to breathe to get rid of it. Your brain asks the muscles in your chest to contract hoping you’ll listen to it. That’s those uncomfortable contractions you start doing. But despite your brain’s best intentions, it’s asking you a little early.
That initial urge to breathe isn’t really a signal that your blood oxygen is low. Rather, it’s a signal that your CO2 levels are high. When you understand that and can work through the discomfort, you’ve got a surprising amount left in the tank.
As you know, as you go deeper, the atmospheric pressure increases. That pressure squashes you and your lungs and the oxygen inside them. This affects your buoyancy, so at about 40 or so feet, you’ll notice that you aren’t floating up anymore. Below that, you actually become negatively buoyant and you sink pretty easily. It’s a strange feeling, but helpful for things like attempting to break world records for deepest dive.
Anyway, that’s basics, which Molchanov knows very well. He’s a 29-time world champion (yes, 29) with 27 world records, and 32 combined gold, silver, and bronze individual and team medals at world championship events. His record-breaking dive happened during the CMAS 10th Outdoor Freediving French Championship. He did it in the Constant weight (CWT) division, which means that the diver “descends and ascends using their monofin and/or with the use of their arms without pulling on the rope or changing their ballast; only a single hold of the rope to stop.”
The entire dive took 4 minutes and 25 seconds, and it netted him yet another record. Watch the whole thing above, and don’t hold your breath. Or do and see how far you get.
