DCS @ < 60 feet

[Lehmann108]

I was talking with someone from DAN a few years back. They told me that they have had reports of DCS happening in four (4) feet of water.

Oh man! I struggle with that one. It must be a misdiagnosis. The person must have spent four years at 4 feet and then suddenly stood-up in his pool.

 

[MookieMoose]

I was talking with someone from DAN a few years back. They told me that they have had reports of DCS happening in four (4) feet of water.

There's got to be some misunderstanding here. At a depth of 4 ft you are only at a pressure of 1.12 ATA, which means breathing air you experience a pN2 of only 0.88 ATA. At this pressure, even if you were completely saturated, an immediate ascent to the surface by standing up would not be able to produce enough supersaturation to generate DCS. A lung overexpansion injury resulting in a gas embolism (DCI, or decompression illness) would be very possible, but there is a big difference between DCS and embolism.

Cam

 

[muddiver]

Ok you silly BESAC divers, here's how you exceed :60 @ 60'.

I use to dive at a large public aquarium to perform maintenence and fish husbandary. If you are using any of the standard tables there is the :10 rule. If you are rather fast at changing out your tank after a dive, and you have been working at 60', you can easiely exceed the table by swapping out you tank in less than :10 on the surface. As a working diver more bottom time is the norm in order to get the work done.

More people would get bent if it was easier to switch tanks and get back in. Fortunately, most dive operators take their time moving the boat from spot to spot and most shore divers are too damm tired to do a fast switch when they climb out.

 

[amascuba]

A person from our group took a Type I DCS (Joint Pain) hit last summer during our trip to Turks & Caicos. All his profiles were conservative, with his deepest dive just under 75fsw. Most of his dives were around 50-60 feet, around 45-60 minutes, doing 3 - 4 dives a day, and with 2+ hour surface intervals. This particular person also doesn't drink any alcohol and only drank water and tea during the entire trip.

Lucky SOB got to say an extra week to do treatments and do some fishing.

 

[ClayJar]

I doubt there are many divers that can do 60 feet for 60 minutes with a square profile on an 80.

Hehe, maybe not many, but there are certainly a few of us. (Of course, it helps that I dive solo most of the time -- I only need enough reserve for one diver.)

 

[loosebits]

A rapid ascent could easily cause a hit in the 40 - 60' range.

 

[MXGratefulDiver]

am i wrong or is it near impossible to do into deco at less than 60feet

as one's air in say an alum80 is going to run out long before 60 min @ 60 feet?

i was reading that above 40 feet it is near impossible, just curious about how and why

aloha from north shore

Going into deco and getting DCS are not necessarily related.

One can get DCS while diving well within no-decompression limits, and one can go into deco and not get DCS.

This should've all been covered in your OW class ...

... Bob (Grateful Diver)

 

[Thalassamania]

If memory serves DCS is usually thought to require a more than 23 FSW (27FSW?). I know of more than a thousand people who spent 12 or more hours at 21 FSW and made a normal ascent to the surface without any symptoms.

 

[String]

Plenty of incidents of DCS <20m/60ft. There was one last year at 10m/30ft for example.

Decompression theory is just that, its a theory, a statistical model. Its not all hard science. Staying within the limits can get you bent especially if you violate ascent rates. Can still happen even if you do everything correct.

The more repeat dives you do in a period the further you get from the models.

 

[Blackwood]

My fiancee has been bent in less than 60'

As string said, it's all theoretical.