How deep can a scuba diver be certified for with tanks of compressed air and a scuba mask?

The recognized limit is 130 feet for an advanced level recreational diver on air. This is not necessarily the limit that a technical diver may restrict himself to. It's not uncommon for a experienced tech diver that dives within their ability, to go to 150 to 170 feet on normal air. I've known a few that have dived 240 feet on a regular basis. They also happen to be experienced and have the proper training and equipment and observe decompression obligations.


That number of 130 feet is just that. A number that the certifying agencies have come up with for the average diver with average equipment and training, that in most cases will be safe for the diver.


The reverse can be true as well. There are some divers who can't get to 90 feet without being seriously nitrogen impaired.


The person that answered that you need a ';nitrous cert'; below 150 feet, and actually plans on diving a nitrox mix at that depth or below...is a dead diver. Nitrox is actually just meant to increase your bottom time but it's a gas that can't be employed deep. Doing so, at 120 feet or more (depending on the mix, even shallower) can actually give you a O2 tox hit, killing you.


What they are probably thinking of is tri mix, a hypoxic gas mix, that has LESS, not more O2. That can actually be used deeper as it can overcome to a degree, both nitrogen narcosis issues as well as O2 toxicity, as long as the mix used is rated for the depth it's employed.How deep can a scuba diver be certified for with tanks of compressed air and a scuba mask?
The recreational dive limit is 130 feet.How deep can a scuba diver be certified for with tanks of compressed air and a scuba mask?
Scuba certifications go something like this:





Open water: 60feet


Advanced : 100feet


Advanced Deep: 130


Technical Decompression: 150


Extended Range 180-200





I personally do not like going much beyond 200' on air since I get 'narked' and it feels like someone is watching me at that depth. Also as another diver responded, you take Nitrox, or oxygen enriched air deep like that and you are asking for trouble. Nitrox is designed to give you more dive time in SHALLOWER dives, not to take you deeper. On trimix, or a mixture of helium, oxygen, and nitrogen, depths are limited only by your credit card company. The deeper you go, the higher pressure the gas you breathe, thus you consume more on each breath. There have been extreme record dives beyond 1000', but that required literally tons of scuba tanks and support people, and it took over 24 hours of decompression for them to return to the surface. Keep in mind this is not on air.





I have been to 200, a friend of mine hit 257' on a photo shoot of a U-boat wreck, but the standard accepted 'limit' for deep diving is 218' on air. at that depth each breathful of 'air' contains as much oxygen as if you took 1.6 breathfuls of pure oxygen, or 8 times as much as at the surface. Beyond 218, the risks of falling unconscious or having a seizure due to Oxygen levels become very high.
150 to 180 ft then you require a deep diver cert. Or nitrous cert.