Give me definitions on a couple of terms?

[DougK]

One area not covered well in my classes were the simple definitions of some classes of diving:

I know OW allows you to dive down to about 60 feet.

AOW down to 130.

I have often heard of divers going much deeper than 130.

What is the technical term for this: Tech Diving, De-co diving? Or is it just called Deep diving? Yep, I know you can stay down long enough for deco at shallow limits.

Is this term of Tech Diving the training for de-co work or is that something else entirely?

Don't over react to this question: What is the practical depth limits of diving with scuba gear? I don't want to do this myself, but I am curious what the equipment can support? Or better yet what the body can withstand? Don't these free divers go down to something like 500 feet? Are there not scuba spotters down that deep on these free dives? With the proper training what is the limitations? I have been asked this question by non-diving friends and I simply don't have a good feel for the answer.

I want to be thinking in the right terms when I hear these terms used in the scuba magazines and on Scuba Board.

 

[H2Andy]

well... tech diving is generally defined as any type of diving where you have
a real ceiling over your head (cave, wreck) or a time ceiling over your head
(i.e. you have to do decompression at a certain depth before you can ascend
further).

deco diving means you are doing decompression. in other words, you are exceeding
the no-decompression-limits of the recreational diving dive tables, and,
again, can't ascend without mandatory deco stops.

generally, if you go below 130 feet, you will need special equipment (such as
double tanks), or special gases (trimix) , and will get into decompression territory
except for very brief dives.

 

[The Chairman]

Diving below 120fsw on air is suicidal for most people. Narcosis makes them as dumb as a bag o' hammers and they can make a simple mistake that will cost them their life. There are quite a few who do this and do it all of the time, and may God watch over their souls.

Free diving starts with a limited amount of N2, so narcosis can't occur.

 

[Matteo]

not being a tech diver myself, I'm sure others will chime in with better answers and definitions, but you can try this on for starters: the respective depths of 60fsw and 130fsw are guidelines and recommendations put in place by certifiying agencies(PADI, NAUI, SSI, YMCA, etc.) and are "generally" accepted within the diving community at large. Yes, going past a depth of 130fsw is considered both "deep diving" and "tech diving", with the latter being a more comprehensive term involving things other than just going deep. And yes, chances are that if you decide to do any diving past 130fsw, you will almost certainly have decompression obligations. How deep can one go, you ask? There are several limiting factors including, but not limited to the type of gear you are using and the type of gas/gases that you are breathing. The two biggest limiting factors would be proper training/experience and comfort level. Hope this helps for now and don't worry, better answers from those more informed and experienced are on the way. IMO, it's not how deep you can go or have been, it's how much fun you've had while you were there!

 

[heligeek]

Well I believe the world record for individuals with a scuba unit is 430ft. The human body can handle pressures because it is mainly water. The limitations that are imposed are based upon the oxygen toxicity, and the ability of your body to handle the dissolved Nitrogen in your body compartments; you will get alot of this training if you decide to take the Nitrox certification or during the Divemaster course Dive physics. Its a matter of PO2 or pressure gradients--PM me if you want to know the science behind it or look up Dalton's Law. Basically Oxygen limits for safe diving is 1.6 PO2 and based upon your mix of oxygen. If you decide to go past 140ft, you will have to use different methods for planning your dive.

As far as the scuba spotters they usually is not scuba spotters and if there are they are using hard hats or suits.

The definitions of the terms are based more upon the type of diving not the depth of the dive. Tech diving is diving that normally uses multiple cylinders and could utilize decompression models during the planning.

 

[Cave Diver]

One area not covered well in my classes were the simple definitions of some classes of diving:

I know OW allows you to dive down to about 60 feet.

AOW down to 130.

I have often heard of divers going much deeper than 130.

What is the technical term for this: Tech Diving, De-co diving? Or is it just called Deep diving? Yep, I know you can stay down long enough for deco at shallow limits.

Is this term of Tech Diving the training for de-co work or is that something else entirely?

Don't over react to this question: What is the practical depth limits of diving with scuba gear? I don't want to do this myself, but I am curious what the equipment can support? Or better yet what the body can withstand? Don't these free divers go down to something like 500 feet? Are there not scuba spotters down that deep on these free dives? With the proper training what is the limitations? I have been asked this question by non-diving friends and I simply don't have a good feel for the answer.

I want to be thinking in the right terms when I hear these terms used in the scuba magazines and on Scuba Board.

Most BOW divers have a depth limit of 60'

Most AOW have a recommended depth limit of 100' with 130' being considered the absolute max depth.

Anything over 130' can be considered an extended range dive.

Some divers prefer to use trimix (helium, oxygen, nitrogen) for any dive past 100' due to narcotic impairment.

Every dive is a "deco" dive, just some dives require longer stops than others.

Practical depth limits are imposed largely by how much decompression one wants to undergo. Open circuit SCUBA dives have been completed to 900' + but were bounce dives and required substantial amounts of logistics and decompression time.

Dives in the 300'-400' range are about the deepest that I'm aware of that are currently being conducted on o/c with an regularity.

To me, "recreational" dives are any dive that stays within NDL limits, have no overhead environment and are not "commercial" by nature.

"Technical" dives are any dive that have mandatory decompression stops, or involve some sort of overhead environment.

 

[PenguinAdLitem]

FYI - I think AOW gets you to 100' with a 130' "contingency depth." In other words, if all you have is AOW you aren't supposed to plan dives to 130, but if your buddy sinks to 130 you can drop down to save her.

I understand anything below 60' to be "deep diving." Dives below 130 fsw are almost all Tec Deep, because you will hit deco limits at that depth before the dive becomes interesting. For instance, on air at 130 fsw with no prior dives on the day, your no deco limit is just 10 minutes on the PADI table, and less if you took time to get to 130 fsw. According to PADI, any dive below 130 is definitionally a technical dive (although H2Andy's definition of technical is correct, and appears to be more accepted).

 

[diver_sam_851027]

I understand anything below 60' to be "deep diving."

SSI certifies to 100'. I don't think AOW changes this limit...I believe the deep diving specialty allows you to 130' - not positive on this have to double check.

I've been to 70' as an OWD and am in the process of reaching my AOW...two more dives...and I'm pretty sure this will not change my limit...it remains 100' until I do the specialty.

 

[heligeek]

SSI certifies to 100'. I don't think AOW changes this limit...I believe the deep diving specialty allows you to 130' - not positive on this have to double check.

I've been to 70' as an OWD and am in the process of reaching my AOW...two more dives...and I'm pretty sure this will not change my limit...it remains 100' until I do the specialty.

Alot of the depths that are handled by the certifications are nothing more than suggested depths and the RDP gives you up to 140 for contingincy uses only, please don't flame me just pointing out not suggesting using 140 as a depth limit.

As long as you can make a safe dive within your limits and training, you can do it. The fact is that a certification is not what governs your actions in the water you are the one responsible for your own depth ratings as well as whatever agreement you have signed with the insurance company.

 

[ZzzKing]

One area not covered well in my classes were the simple definitions of some classes of diving:

I know OW allows you to dive down to about 60 feet.

AOW down to 130.

I have often heard of divers going much deeper than 130.

What is the technical term for this: Tech Diving, De-co diving? Or is it just called Deep diving? Yep, I know you can stay down long enough for deco at shallow limits.

Is this term of Tech Diving the training for de-co work or is that something else entirely?

Don't over react to this question: What is the practical depth limits of diving with scuba gear? I don't want to do this myself, but I am curious what the equipment can support? Or better yet what the body can withstand? Don't these free divers go down to something like 500 feet? Are there not scuba spotters down that deep on these free dives? With the proper training what is the limitations? I have been asked this question by non-diving friends and I simply don't have a good feel for the answer.

I want to be thinking in the right terms when I hear these terms used in the scuba magazines and on Scuba Board.

One other thing no one touched on is that the term "freediving" refers to individuals diving with no scuba gear. They take a BIG breathe and head down, just like you did in the pool as a child. I think the world record for that is in the neighborhood of 400' and was accomplished by riding down a specially made, weighted sledge.