One of the first forms you sign when you begin a SCUBA training course, no matter what agency or level of training, is a medical statement informing you of risks that pre-existing health problems may cause. The following is the Recreational Scuba Training Council’s [RSTC] generic medical statement:
“Diving
is an exciting and demanding activity. When performed correctly, applying
correct techniques, it is relatively safe. When established safety procedures
are not followed, however, there are increased risks. To scuba dive safely, you
should not be extremely overweight or out of condition. Diving can be strenuous
under certain conditions. Your respiratory and circulatory systems must be in
good health. All body air spaces must be normal and healthy.” (Recreational
Scuba Training Council, 2007, p. 1)
The rest of the form is comprised of yes or no answers on if you have or have ever had certain medical conditions, such as asthma, frequent colds, any form of lung disease, blackouts or fainting, to name a few. While none of the statements would necessarily disqualify someone from SCUBA diving, they recommend you discuss it with your family physician before continuing.
As mentioned by RSTC medical statement, to dive safely, it is best if you are in good physical condition. Upon completing the paperwork, and beginning open water training, there will be an expectation that you can swim, in addition to lifting and carrying between thirty and forty-five pounds. In the Professional Association of Diving Instructor’s [PADI] Open Water Diver course, there are five confined water dives in a swimming pool, and four open water dives. The practice in the confined water serves to introduce important skills, including assembling and disassembling the SCUBA gear, how to inflate your buoyancy compensator [BC], breathing off your regulator, what to do if your mask accidentally gets flooded with water, and how to communicate underwater with basic hand signals. Swimming skills are required. The following water skills according to the standards have to be assessed: before the second open water dive, a 10 minute swim/float without any swim aids; before certification, a 200 meter/yard continuous surface swim, any style, or a 300 meter/yard swim with mask, fins, and snorkel. (PADI, 2007, p.2-3)
The biggest area of exercise, I would say, required for enjoying SCUBA diving would be cardiovascular. Your lungs, heart, and bloodstream all play a role in how long you can enjoy the underwater world. One of the hardest skills I found in the confined water at my Open Water Scuba Instructors course was the Controlled Emergency Swimming Ascent [CESA]. The skill is to simulate an out-of-air emergency where you do not have a buddy nearby to provide additional assistance. The goal is to swim 30 feet at a reasonable rate, while making a continuous “ahhh” sound to prevent yourself from holding your breath. Part of the reason it is challenging in the confined water environment is because the physics of water pressure are not working for you, where in the open water they are. In the open water, it is a vertical swim from thirty feet to the surface in thirty seconds. As you ascend from that depth, the air remaining in your lungs expands. With a good comfort level in the water and practice, it is doable, even enjoyable.
Before you go in the water, you do need to be able to lift equipment. The heaviest item is the aluminum or steel cylinder that holds the compressed air for the dive. According to a chart from Huron Scuba (2004), the exact weight does vary by manufacturer. For the standard aluminum eighty cubic foot tanks that you can find as rentals at many dive shops in South Florida, the weight range is from thirty-one pounds to thirty-five pounds. The tanks I dive with, steel eighties are about twenty-eight pounds. Both sets of those numbers are empty weight without the valve. The Buoyancy Compensator (BC), Wetsuit, Regulators, Mask, Fins, and Snorkel add about another five to ten pounds. If you own your gear, the after dive weight of the wetsuits are also heavier from the salt water, and from the fresh water used to rinse the salt water off.