Altitude diving is like nothing else, but does pose some unique challenges. Because of reduced atmospheric pressure at the surface, and because almost all altitude diving takes place in fresh water rather than saltwater, depth gauges are affected; when you ascend after your dive, the rate of change that occurs as ambient pressure decreases is much greater than that which occurs when you ascend from a dive in saltwater at sea level. Let’s take a closer look at altitude diving, its physiology, and some specific dangers associated with scuba diving in the mountains.
Compensating for an Increased Risk of Decompression Sickness
DCS can happen after any dive if precautions aren’t taken, but the risk of developing decompression sickness following a dive at high altitude is far greater than that at sea level. Dives that one might consider to be relatively safe in the ocean can generate many more bubbles within the body at high altitude, leading to DCS symptoms ranging from a mild rash to paralysis or even death. This happens due to pressure variation between the gas that is inhaled and the body’s mechanism of moving toward equilibrium with existing pressure in the environment. When you ascend into a low-pressure environment such as that which exists at high altitude, tissues are at risk of carrying higher pressure gas inside than that existing outside, and as this gas attempts to move toward equilibrium, DCS can occur.
Following dive tables with scrupulous care and ensuring that your computer is functioning properly are two of the best ways to compensate for the increased risk of decompression sickness; taking extended safety stops is another way to help make the transition from a pressurized environment to a low-pressure environment easier on your body.
Why Dive at Altitude?
With the increased risk of DCS, why is it that so many people love diving at high altitude? There are many reasons: Some of us live too far from the ocean to allow for frequent dives in the sea, and must keep in practice by diving in mountain lakes. Some of us love ice diving, and we find that mountain lakes offer exceptional visibility particularly during the winter. Some divers just love the challenges associated with diving at high altitude, and some explore mountain lakes in hopes of finding important artifacts such as the many WWII remnants believed to be contained within Europe’s many lakes.
No matter what your reason for diving at altitude, remember that mountain diving does come with greater risks than does scuba diving at sea level. By taking a conservative stance when it comes to giving your body the chance to acclimatize before diving, by ensuring that your safety stops are sufficient, and by ensuring that you’ve given your body the opportunity to eliminate built-up gas bubbles before flying, you can greatly mitigate those risks. Ensure that you are properly trained before diving at altitude, and remember never to exceed the limits of your training and experience, and you’ll be taking important steps to ensure your safety while enjoying the tranquil underwater that beauty mountain lakes have to offer.