Pre-Dive Tank and regs Prep: Worth It?

[Njord fr]

Hello everyone,

Is there any benefit to submerging your tanks and regulators in the water before diving? I see many fellow divers putting their tanks with regulators mounted on them into the water long before they change and get into the water themselves. Is there any advantage to this? Especially to prevent regulator freezing?

Another question, when opening the air inlet valve of your tank, is there any benefit to opening it slowly rather than quickly?

Thanks!

 

[inquis]

Carrying heavy gear before getting into your drysuit up allows the sweat to evaporate, keeping you drier/warmer. It's often easier to make several trips with lighter loads. Leaks are also easier to detect in the water, and it's nice to deal with those sooner rather than make everyone get out of the water at the last minute.

For cave diving, cooling tanks to ambient temperature yields a more realistic turn pressure/indication that maintains the desired reserve amount.

I'm not aware of any benefit concerning regulator freezing. [Edit: here I meant freezing in cold water, but @rick00001967's post reminded me that some care needs to be taken if air temps are near/below freezing.]

 

[rick00001967]

are we talking about ice diving? or at least diving in extremely cold water / air temps?

if that is what you are asking about, then yes, many divers will lay their bcd with the tanks and regs attached, in the cold water.

it is suggested not to breath from the regs on the surface when diving in cold weather. it is better to keep the regs in the water. then test them with the reg in your mouth and your face in the water.

only other reason i see is that many will lay their bcd in the water to get the straps wet. but this is done prior to attaching the tank. it can help prevent the straps from loosening.

 

[tursiops]

Another question, when opening the air inlet valve of your tank, is there any benefit to opening it slowly rather than quickly?

Yes. The pressure pulse from the quick opening can damage the high-pressure seat in your regulator.

 

[TMHeimer]

I never submerged it prior to diving and at times dives in 35F water with no problems.

 

[Marie13]

I’ve been diving in the winter multiple times in 48-50F water with air temps below freezing and wind chills below 0. You have to put your tanks in the water as soon as they’re assembled so the regs don’t freeze. At least once after those dives, my first stages were frozen to the tank, so I just threw them in the car that way b

 

[TMHeimer]

I’ve been diving in the winter multiple times in 48-50F water with air temps below freezing and wind chills below 0. You have to put your tanks in the water as soon as they’re assembled so the regs don’t freeze. At least once after those dives, my first stages were frozen to the tank, so I just threw them in the car that way b

Perhaps this is more likely to occur in fresh water?

 

[NW Dive Dawg]

I also believe that slow opening of a tank valve is always a best practice for tanks with high concentrations of O2.....up to and including 100%. And as @tursiops correctly mentions, overall best practice is to always open any valve slowly as it is less impactful on the HP seats.

 

[Marie13]

Perhaps this is more likely to occur in fresh water?

yep, this was fresh water b

 

[halocline]

Keep in mind the HP seats are sealed with IP, not supply pressure, so I’m a little skeptical that opening the tank quickly will damage them. I suppose you could do an experiment; hook up an IP gauge and watch it when you open the tank valve. It’s not going to bounce up and then back to IP, it’s going to basically rise to IP and stop there. I’m pretty sure it will do that no matter how fast you open the valve.

The fast valve opening could put more stress on the o-rings that actually seal HP air, I guess. For mixes with high FO2, then definitely you want to open the valve slowly, but that’s about not creating any heat as the gas in the 1st stage HP chamber gets compressed.