You don't always want to put air into your BC. Many of the drift entries in SE Florida are quick, negative entry dives. Simply pre-breathe your reg to check if your cylinder is on.
:shrug: Wasn't part of my OW course. YMMV and all that.
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You don't always want to put air into your BC. Many of the drift entries in SE Florida are quick, negative entry dives. Simply pre-breathe your reg to check if your cylinder is on.
I can say in PADI Divemaster training we turned our air off underwater - reading thru the standards, I'm not clear if it really should be taught that way.
Another problem is overly "helpful" boat attendants. I like to set up my own gear and turn my air off for the trip out in the boat then turn it back on just before putting on BCD. More than once someone has started goofing with my air just before I enter the water. At least once my air was turned back off.
This allows them to descend very quickly and any residual air in the BC is quickly compressed and with only partial inhalations their lungs are not providing much buoyancy , they stay negative and can power down to 30 feet while only taking in one or two half breaths.
I had geared up on my second tank during the surface interval, checked connections and tank pressure then shut the valve off as usual. What I didn’t do was PURGE the residual air out of the system. Moron! However, I DID remove all the air from my wing for the next hot drop. The captain finally yells dive, dive, dive! Glancing down at my SPG I see 3600 psi, so I hit the water with my heavy steel HP120,
I simply placed my left hand under my tank and pushed upward, then raised my right arm over my shoulder and grabbed the valve to turn it on, all while finning towards the surface. By the time my head broke the surface my air was on and I was ready to continue with my hunt.
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A-HA! That is a good idea. I might start putting my tank higher from now on.I dive with my tank higher than most because I typically don’t carry any lead, especially when diving steel tanks. I use the tank position to distribute weight higher. What I have noticed over the years is how very LOW many divers place their tank. The tank is hanging halfway down their butts, so the tank valve is down in the middle of their back. Seems like it would be difficult to turn your air on without removing your BC if you “decide” to attempt diving with your air off.....
Edit: this is not meant to be a negative comment with regards to how people mount their tank. That is a personal preference. It is just an observation.
WOW. I've never heard of that. This is sort of off-topic, but how do they equalize that fast? And is the reason for getting down that quickly is that it's a drift dive with a really strong current at the top?
Or is it for super-deep diving where air consumption is super-important, and they want to eliminate as many breaths as possible?