I lost 2400psi in 30 seconds

[Stirling]

I might have taken the octo and saved the little bit of air in my tank "just in case". On the other hand, that would be one more thing to manage during an already stressful ascent.

I agree with that; if I were in a situation where my remaining air supply was very marginal but my buddy had plenty of air, I would want to conserve the little bit of air remaining in my tank and breathe off my buddy's air all the way to the surface, if possible. You don't really know how much air you need to get to the surface until you get there, or what might happen to cause you to be separated along the way.

Worst case (that occurs to me at the moment), you run into an entanglement problem while she has the uncontrolled buoyancy problem just as you are expecting to reach the surface with an empty tank. Or maybe you just have a reverse block that makes ascending a problem for a couple of minutes. They may be long shot scenarios, and if you were closer to the surface and still had a few hundred psi I wouldn't bother, but at the point when you were starting up from 100' and only had 600 psi, I would join Scot M in wanting to keep that 600 psi "just in case" something else happened along the way to the surface.

 

[Stirling]

Wow thanks for sharing. Seem to me the moral here is to check your gage just be fore descent and not just on shore or the boat. I usually do this because I check the loss of PSI on entering the cool water since I have steel tanks that heat up on filling quite a bit.

Shouldn't everybody be looking at their SPG or computer to check their air pressure while breathing off their regulator just before stepping or rolling into the water? (Not only on the surface just before descending, but before entering the water.)

I think it has been noted earlier in this thread that this is how you confirm that your air is actually turned on. Forget having to end the dive prematurely because the tank is nearly empty. One of the more common causes of panic and drowning at the very start of a dive is stepping into the water with your air turned off.

Too many people hit the water and sink with a regulator in their mouth that won't deliver any air because the valve is closed or nearly closed (and the BC is not inflated and they are carrying too much weight and all of those other things that all seem to come together at once in these cases), and they sink without remembering to dump their weights and without having time to figure out why they can't breathe (much less reach the valve and turn it on), and drown before anybody else can catch up with them.

*That* is a deadly hazard, and *that* is the reason for checking your air pressure at the very instant that you are breathing from the regulator immediately before entering the water.

 

[divereh]

I’m new to these boards, but have been diving for about 2 years. I’m AOW with about 20 dives beyond those of the certifications.

I think it’s great that we can all learn from each others mistakes. Although it wasn’t life or death drama, I’d like to share one of my mistakes with you all.

My buddy and I were diving out at Casino Point on Catalina a few weekends ago. It was a busy day, but not super crowded like it gets in the summer. We started the rental paperwork at the trailer rental place there by the water and started to suite up. When the rental dude brought our tanks out, I took my reg and checked my tank (3000psi) then I took my reg and checked my buddy’s tank (3000psi). I put my reg back onto my tank and we both suited up.

At the waters edge, we reviewed out dive plan and performed our checks on each other. Here’s mistake #1. I checked my air by taking a few breaths through my regs. I neglected to verify my pressure again on the gauge. But heck, why should I? It was reading 3000 about 15 steps ago when I put my gear together, right?

We did our surface swim out to our point of decent. When we got there, we rested for a moment to catch our breath and did another equipment check. And (#2) I checked that my air was on and regs worked, but didn’t bother to check pressure. What’s the point? I’d only taken about 3 or 4 breaths from it since I checked it on land.

So we switch to regs and descend to the Valiant - a wreck about 100’ down. Once we’re kneeling on sand we give each other the OK sign and show each other our pressure gauges. Imagine my surprise when I’m reading 600psi. Holy crap! How did I burn through 2400psi on just a 100ft descent? Well, it doesn’t matter now, time to go back up.

After puzzling it over for a while we figured out what had happened. The way the rental place works is when you get a fill on your rental tank, you simply drop of the empty and pick up a full. And since I was gearing up close by, another diver accidentally mistook my rental tank for one of the refilled tanks anyone can take. So while my back was turned checking my buddy’s tank, my 3000psi tank got picked up, and an identical 600psi empty left in its place. I dropped 2400psi in about 30 seconds.

So the lessons I taught myself that day…
1) Checking your air means taking some breaths, AND checking the pressure (even if you just checked your pressure a few seconds ago)
2) Check your buddy’s air pressure. Don’t assume (as my buddy did) that your buddy is smart enough to do it for himself.
3) It’s just as important to be cautious and thoughtful before you dive, as it is while you’re diving.
4) Getting my own tank with distinctive graphics might not be a bad idea.
5) A dive with less than one minute of bottom time is no fun.

-- George

IT'S ALWAYS THE EQUIPMENT,NEVER THE DIVER, ANYONE ELSE EVER NOTICE THAT.
DIVEREH

 

[KrisB]

IT'S ALWAYS THE EQUIPMENT,NEVER THE DIVER, ANYONE ELSE EVER NOTICE THAT.
DIVEREH

Actually, no. George was blaming himself for this -- reread the post you quoted -- especially the points he makes at the end. #s 1, 2, and 3 are all diver-related, #4 is a possible equipment *solution*.

 

[pete v]

I always wondered why we looked at the guage when we pulled a breath. This certainly explains why we shouldn't shortcut this step. Thanks for the post. Good lesson for us not to get too complacent.

i learned that the hard way in ow class at the pool, opened my tank after everthing was connected and when it was time to get in the instructor was interupted from the class and when he left he told us to hang tight, as a newbe i did what any other newbe would do....play with all the "new and interesting"gear well in all my wisdom i turned off my tank....to make a long story short the instuctor came back in and said don your bc and in the pool. well i did and like a good newbe i manually inflayed my b/c to save air and checked my gauge "3000 psi"and in the pool i went and down i went took a few breaths and from that point i was the example for the class and why you breath through the reg and check your air supply on the gauge. you can learn alot in a short period of time

 

[PerroneFord]

I realize I'm the newbie here, but isn't it customary to mark your tanks? I know I will be putting a fat piece of tape on mine (rental or owned) with my initials on it. Not like you need MOD or anything on basic OW dives, but just something to indicate your tanks are YOURS. Probably would have saved a ton of confustion in this case.

This was good to read though as I am gaining knowledge from other people's issues.

Thanks for sharing your story.

 

[DeepDog]

I can't imagine not checking pressure at some point before descending but then most mistakes we make we can't imagine ourselves making

Thanks for sharing the experience.