Deep diving is never a cool thing to show or a mystery that should exclude amateurs. It can be just a hobby and a way of entertainment for anyone who is really into it and both mentally and physically ready.
Deep training is offered by all the Scuba Agencies. Let’s presume that by “deep” you mean deeper than 30 m. (Although Padi defines “DEEP” as any dive below 18 m). Deep training is an extension of and builds upon the Scuba Diver training you already have. Different dive qualifications take you to different depths. (Actual course names may differ depending on Agency). The risks of Scuba increase exponentially the deeper you go, you need to understand these risks and have the correct skill set to manage them.
Deeper Diving considerations include but not limited to:
1. Narcosis when breathing nitrogen and oxygen in enough density (caused by depth)
2. Gas depletion scenario will be much more fatal than it is in shallow dives
3. Much faster Gas consumption (with SCUBA, caused by depth)
4. Long deco stops require multiple tanks
5. Longer and multiple level decompression procedure require excellent depth control
6. Multiple gas on board require much more gas management knowledge and a clear mind
7. Oxygen toxicity caused by deco gas swap at wrong depth
8. Staying down doing tasks is easier than going up manage deco stops
9. A extremely deep dive will require gas content of lower than 17% trimix which is not life supportive in shallow water but can avoid oxygen toxicity at bottom depth
10. A dive buddy you trust and team work are very important
In most of scenarios we don't go deep just for the sake of it, we go deep because there is something to see. Some of the best wreck diving is deep. There are some fantastic deep “blue holes” around the world.
The guy who is always bragging about how deep he has been is not a deep diver, he is either a liar or an untrained fool. Qualified deep divers don’t sound off.
Training for the deeper stuff takes dedication, application and the development of the right mindset.
What Rebreather can do for your deep dives?
To reduce narcosis, we need less nitrogen in the gas content. In order to avoid oxygen toxicity, the percentage of oxygen in the gas used may be less than it is in air. Helium which causes little narcosis is the ideal gas to replace part of nitrogen and (when too deep) the necessary amount of oxygen to support a diver’s deep dive. We call it a hypoxic trimix. The only disadvantage of Helium is the price. Why sport technical divers would eventually go for CCR? Besides the bail-out system makes CCR dive safe, here is a example for a better understanding on helium costs:
If a 60m trimix dive with bottom time of 20 minutes is executed in a safe and proper way, for a person with excellent gas consumption, the Helium will cost you approximately 240 usd on traditional Open Circuit; with all other conditions remain the same, around 30 usd will be the cost for Helium on Closed Circuit (CC).