What are the differences?
Some of you neophytes might be wondering. What if any differences are there in the three categories: deep diving, wreck diving and recreational diving in general?
Open Water Certification
When you become a PADI open water diver, you the bearer of the card are certified in basic areas. That is a recreational diving certification.This includes diving to 20 meters or 60 feet. In general, at this depth a surface swim is possible and visibility is generally enhanced by the sunlight—if any on the day of the dive. Air consumption is generally between one half and one third in terms of volume available. With increased pressure, the volume of air available decreases proportionately from the surface volume.
You could also use the term ATM or atmospheric pressure. Every ten meters is one ATM or atmosphere. Therefore, two atmospheres gives you exactly have the volume of air available, and three atmospheres gives you one third. So if you are figuring how much air your breath on the surface and how much time it takes to breathe it, you can easily figure how much time it would take to consume the air at one ATM or two ATMs or for that matter any ATMs.
Surface Air Consumption
In technical diving, figuring SAC or Surface Air Consumption is done by swimming along at the surface for a few minutes. In this manner, they determine how much air was consumed. Then it is just a matter of dividing the volume used by the atmospheric levels. The determination of how much air you anticipate in using at a different atmospheric level is proportional to the atmospheric pressure. The level of air consumption is still the same, however, the gas itself is compressed when it comes out of the tank and the second phase of the air regulator (that’s the mouthpiece).
How Air in the Tank works
The air in the tank is the same pressure regardless of how deep you go! The tank itself is sealed by a valve that only opens when the air is demanded from the regulator (breathing apparatus). FYI, after the air is released from the tank through the first stage of the regulator, the pressure of the air is adjusted. It ranges approximately 110-135 pounds per square inch or PSI.
Regardless of the amount of air in the tank (provided you have any to begin with) a properly adjusted regulator will consistently display this pressure on a pressure gauge. This is to ensure that regardless of air pressure in the tank the air pressure stays the same in the breathing apparatus. If your tank is one-third full or completely full, the regulator “regulates” the air pressure. This ensures the ease of breathing. It does not get harder to breathe as you go deeper. With less air in the tank, provided of course you are within the pressure parameters for accessing air in the first place the ease of breathing will be about the same. Obviously, if the tank is empty you cannot draw air out! The tank would simply be the same pressure as the surface atmosphere or 1 bar. In this situation, there is no pressure!
If you are interested in learning how to become a service technician of regulators, try A.S.S.E.T.. Steve Burton is a world-class expert in scuba dive engineering as well as electrical engineering. He’s got great stories to tell as well!
Diving for general fun or recreational diving is diving up to 40 meters or 130 feet. At this point, nitrogen narcosis can be felt, and the length of time due to reduced air availability (you are now five atmospheres down). Therefore you have 1/5 the amount of air availability. There are also limits in time for no-decompression dives to 12 minutes at 40 meters. If by accident you go to 50 meters—which is six ATMs, you have only 8 minutes. After that, your dive becomes a compression dive, and you must “decompress”. This is no longer a recreational dive scenario.
Most dives between five and thirty meters
Most dives are conducted between 30 meters and 5 meters. So when you dive the wrecks, deeper dives are generally to be found at sunken wreck sites—which are plentiful in the world. After 20 meters this would also comprise a deep dive according to the Professional Association of Dive Instructors. This would be the vicinity of wreck diving in general, although wrecks can go as far down as the ocean floor–and that’s pretty deep. Some technical divers go all the way to 300 feet or 10 ATMs.
However, it is still a recreational dive!
Just for the record, we find that there are ships sitting in water deeper than 30 meters. These ships can only be enjoyed via technical dive training. For you to attain skill proficiency down the road is possible. However, that is way beyond the scope of recreational dives—but not impossible for you to attain skill proficiency down the road. Mermaids Dive Shop in Pattaya has expert instructors should you want to go that route. If you are on Koh Tao try Crystal Dive Resorts. They’re super! The deeper the dive the shorter the time sequence from descending to ascending. So if you want to spend a leisurely time in the water you must dive in waters less than 20 meters. You might find it a more relaxing scenario as well.