Is DCS possible under 20fsw, or 100% impossible?

[Nitrox_DiverNY]

Hello all, I am curious to know if it is even possible to develop DCS on air under 20fsw while within NDL and while being conservative? Say a water temp of 65F. Is it even physically possible for one to become bent under 20fsw or 100% impossible? Sorry if this is stupid question, its just been something I've been thinking about since a few dive locations by me are in the 15-20fsw range. Thanks!

 

[Marie13]

It is an odd question. I don’t know about DCS, but you can definitely get an AGE coming up from that shallow holding your breath. What concerns about about DCS and these shallow dive sites?

 

[Nitrox_DiverNY]

It is an odd question. I don’t know about DCS, but you can definitely get an AGE coming up from that shallow holding your breath. What concerns about about DCS and these shallow dive sites?

im just curious if DCS even physically possible under 20ft, and I agree about AGE definitely don't want to do any breath holding

 

[Jeremy Williams]

DCS from a single dive at that depth would probably require an extraordinary amount of time underwater and would still be “hard to accomplish” even if you were purposely trying to get bent from a many-hour 20ft dive. But we don’t really understand DCS in any fundamental way. People get bent when they “shouldn’t” and we don’t really know why. No depth of dive is 100% completely free of DCS risk.

 

[Nitrox_DiverNY]

DCS from a single dive at that depth would probably require an extraordinary amount of time underwater and would still be “hard to accomplish” even if you were purposely trying to get bent from a many-hour 20ft dive. But we don’t really understand DCS in any fundamental way. People get bent when they “shouldn’t” and we don’t really know why. No depth of dive is 100% completely free of DCS risk.

Thanks for the feedback, safe diving!

 

[Johnoly]

... Sorry if this is stupid question,

ScubaBoard is very lucky to have a noted and very prominent DCS research doctor (amongst many here). You might want to ask for links to some of his recommended articles he's written to explain the basics of how DCS works. He's @Dr Simon Mitchell

 

[scubadada]

Hi @Will_

Your question got me interested. First I looked up the NDLs on the DSAT and PZ+ tables. The tables start at 30 feet. On air, the NDLs are 4:20 for DSAT and 3:17 for PZ+

So, I went to MultiDeco. I could not find a deco dive at even 24 hours until I lowered the GF high to 60, then you get a whopping 7 min of deco. So the practical answer to your question is no to being able to exceed the NDL. Does not answer the question about being able to have an episode of DCS, but that is likely no also. I don't know about you, but I could only make a little under 2 hours at 20 feet with an AL80

 

[skippy311]

It is an odd question. I don’t know about DCS, but you can definitely get an AGE coming up from that shallow holding your breath. What concerns about about DCS and these shallow dive sites?

Now I'm interested, what's the question?

 

[boulderjohn]

We just finished a mammoth thread nearly the same topic. It finally came to an end with research on shallow saturation divers. It was found that shallower then 20 feet, a saturated diver could go directly to the surface. Deeper than 20 feet, the potential for DCS started to rise sharply. That means that, yes, you can dive shallower than 20 feet for as long as you wish.

 

[GreggS]

Most DCs I've seen don't even start computing No Deco time until they get below 30 feet deep. As others have stated, you would need to intentionally have to stay at 20 feet for an extremely long time before getting a DCS hit. And we're talking many, many tanks of air for quite a number of hours.