What Is High Altitude SCUBA Diving?
Candace Reno December 8th, 2024 Posted In: Articles Tags: SCUBA
When you think of SCUBA diving your mind almost immediately thinks of the ocean. But did you know you can SCUBA dive in lakes, rivers, and pretty much any body of water that is safe and deep enough? Besides diving at sea level, you can also dive at high altitude. What exactly is high altitude SCUBA diving and are there any diving altitude restrictions? Find out below!
What is High Altitude SCUBA diving?
Any elevation greater than 1000 feet is SCUBA diving altitude. There are special rules and procedures to follow for altitude diving. Failure to be properly trained and aware of the altitude diving rules can lead to serious injury or death. Please be safe!
Elevation
Most recreational high altitude SCUBA diving takes place below 8000 feet. There is not a lot of research on higher altitude diving and it isn’t recommend for those prone to health problems.
Sea Level vs High Altitude Diving
The biggest difference between diving at sea level and diving at high altitude is that the atmospheric pressure is decreased as you increase elevation. That means that while SCUBA diving at elevation, you surface to a lesser atmospheric pressure.
Based on physics, this makes your absorption of nitrogen different than if you were to ascend at sea level. The rules of altitude diving are very important to follow to help reduce your risk of decompression sickness or other injury.
Altitude Diving Rules
There are several rules of altitude diving. Some of the top rules and considerations to take when high altitude SCUBA diving are:
Know Your Theoretical Depths
There is an altitude depth chart for SCUBA diving. Based on the elevation you are diving at and the actual depth you are going to, there is a matching theoretical depth. This theoretical depth is what you base your no decompression limits on. This is very important and very serious to understand and do properly. Without knowing your theoretical depth, you can easily exceed your no stop limit and not even know it until you are back on land and possibly feeling symptoms of decompression sickness.
There are many dive computers that will allow for an altitude adjustment. Some computers self-acclimate to your current altitude while others require you to input the elevation you are at. Some dive computers do not adjust for altitude at all and you will have to rely solely on the altitude diving chart to know your limits. There are also capillary depth gauge watches that were the original way divers could know their theoretical depth based on pressure before the dive computers of today came out. These are not always as reliable at given depths.
Slow Your Ascent Rates
At sea level, the ascent rate is 60 feet per minute. At altitude, this ascent rate slows to 30 feet per minute. As always, your ascent rate might be slower on your dive computer which is what you should follow.
Limit to Two Dives a Day
Since there is not a lot of research on altitude diving, it is recommended to only make two standard SCUBA dives each day. This is in order to limit your nitrogen exposure while at high altitude.
Wait to Dive
If you plan to dive at an elevation greater than 8000 feet, you need to wait 6 hours to dive after arriving at your elevation.
Protect Against High Altitude Exposure
If you don’t live at altitude, then your body needs to adjust when you arrive at high altitude. This can lead to an increased demand for oxygen and overexertion. You might also find yourself in colder environments with the need for added thermal protection such as SCUBA diving wetsuits and wetsuit accessories both below and above the water.
Why SCUBA Dive At High Altitude?
You might be wondering why someone might want to SCUBA dive at high altitude. The ocean is full of sea life and that is usually what people get into SCUBA diving for. However, high altitude SCUBA diving can offer some unique places to dive. For instance, in Utah where I live, there is a world famous geothermal hot spring called the Utah Crater at the Homestead resort in Midway, Utah that offers some unique diving at just under 6000 feet in altitude. The temperature of the water is around 95 degrees Fahrenheit year-round! There are some unique features underwater on the walls. This crater is mostly used for training purposes for the local dive shops.
In the United States, popular places for high altitude SCUBA diving include Lake Tahoe and Yellowstone Lake. Around the world, Lake Titicaca in Peru and The Pyrenees mountains are some of the most dove high altitude dive locations. Lake Titicaca is just above the recommended recreational limit at an elevation of 12,500 feet.
Record Highest Altitude SCUBA Dive
The highest elevation that anyone has ever dove on record was at 20,980 feet! This was done in Ojos del Salado in Argentina in 2019 by Marcel Korkus. Before this dive, Philippe Reuter, Claudia Henriquez, and Alain Meyes held the record since 2007 by diving at an elevation of 20,000 feet near the summit of the Pili volcano in Chile. In the United States, the highest altitude for SCUBA diving was set in 2013 by John Bali at 13,420 feet at Pacific Tarn Lake in the Rocky Mountains.
High altitude SCUBA diving can offer a unique diving experience. Make sure you know the rules and consider getting certified in altitude SCUBA diving before you give it a try!
