Using different computer conservatisms for cold water diving

[Diving Dubai]

On my PADI DM theory, it stated that (with tables) its good practice to add 10' to you planned max depth in order to increase your conservatism. This got me thinking.

Those who know me, will know that cold water diving is as alien to me as paying taxes

My question - Is this still a recommended practice? Or has this dropped by the wayside (as computers are generally more conservative than tables)

Do people change the conservatism of their computer, or do they just leave it on their preferred setting whether its warm water or cold water?

While mentioned in other threads their hasn't really been an answer.

 

[shurite7]

This will depend on the diver and his/her knowledge of the dive computer. Most people whom I know do not bother with it. Usually they get cold before the conservative factor plays a role.

Making your dive more conservative when diving in cold water is still recommended, whether diving with a table or a computer. Some computer manuals advise making the dive shorter when diving in cold water.

 

[TMHeimer]

This will depend on the diver and his/her knowledge of the dive computer. Most people whom I know do not bother with it. Usually they get cold before the conservative factor plays a role.

Making your dive more conservative when diving in cold water is still recommended, whether diving with a table or a computer. Some computer manuals advise making the dive shorter when diving in cold water.

Agree on all here. As well, I would imagine depth is important. If you're doing shallow 30-40' dives I would think planning as if 10' deeper wouldn't matter much if at all. At deep depths it would seem prudent.

 

[KaptaniDerya]

I drive in cold water regularly. Haven't changed my computer's conservatism because of cold water. It is what you are used to, I guess. I suspect rgbm and scubapro's adt mb algorithm takes the water temperature into consideration when it is calculating ndl limits.

 

[tbone1004]

i dive cold regularly. I will reduce my GF-Hi if diving in cold water with planned deco. I typically don't adjust it from 50-80 for recreational dives, since I don't really care if I go into deco if diving with someone bound by NDL's, I'll just stay with them until they're done. If doing planned deco, I'll typically change to 50-70, but that is rare. I don't like cold water enough and where we are, there isn't anything worth staying down that long for

 

[t-mac]

Interesting question, but for me anything below 76 F is cold water diving. (I don't adjust. )

 

[tbone1004]

important to note that it isn't necessarily water temperature. I.e. I feel more thermal stress diving my 5mm in a cave for 2 hours at 70F at 60ft than I do diving the same suit for an hour in OW at 20ft when the water is 55F. The factor for me isn't determined by ambient temperature, and nor should it be for anyone, it is determined by my anticipated thermal stress for the dive which the latest research is showing impacts the on and offgassing rates of inert gasses. The other one, is if I'm diving in a super cold quarry that is quite deep, but there is a wicked thermocline and the surface is close to 80, I'm going to have a pretty good boost at getting rid of that inert gas when I come up for my decompression stops so I probably wouldn't give a more conservative factor to that dive. I get extra warmth from the wetsuit rebounding as well as the thermocline.

It's a lot more than looking at ambient temperature....

 

[TMHeimer]

tbone, Thank s for pointing that out. I was always under the impression the only reason at all to plan 10' deeper was the effect diving in cold water has on offgassing. I suppose there may be some correlation between what one considers "cold" as opposed to the next person (usually based on the climate where you live). I would assume this is as grey an area as DCS in general--ei. the point that you can follow all the rules and on a rare occasion still get bent.

 

[tbone1004]

tbone, Thank s for pointing that out. I was always under the impression the only reason at all to plan 10' deeper was the effect diving in cold water has on offgassing. I suppose there may be some correlation between what one considers "cold" as opposed to the next person (usually based on the climate where you live). I would assume this is as grey an area as DCS in general--ei. the point that you can follow all the rules and on a rare occasion still get bent.

cold slows ongassing which is good, but it also slows offgassing, which is quite bad.
Heating Solutions
if you scroll down there, there are links to two podcasts that Dr. Pollack did with Pod Diver Radio on the subject. The links to the articles should be in the podcast links