OOA with a faulty SPG

[Web Monkey]

I rented the BCD, computer, and reg from the dive shop. As I was donning my equip for the first dive, I checked my SPG and noticed it was at 2500 psi. I thought I just got a tank that wasn't full. They changed the tank and at 3000 psi I was good to go. It happened again on another dive but this time the boat crew curiously looked at me and the tank, then gave the SPG a thwack. The needle popped back up to 3000 psi...

FWIW, anything you're diving with can fail at any time, with no warning at all. Tank valves can clog; there have been cases where regulator first stages have simple cracked and split in half, second stage hoses unscrew, crimps pop off. I could go on, but the "take away" is that there's no guarantee that just because you took a breath doesn't mean you can do it again in a few seconds.

This is a really good reason to dive with a buddy you trust, and keep your skills sharp. As long as you have a good buddy, maintain close
"buddy distance" and you both do good gas planning, most "emergencies" can be reduced to interesting annoyances.

Terry

 

[RAWalker]

even a resort diver should have an idea, after a few dives, of how long an Al80 will last at a given depth. I don't think it's responsible to tell people that it's fine not to learn any more about gas management because an AI computer will do it for you. Not everyone has an AI computer; not everybody wants a console computer, and wrist-mounted AI computers are both significantly more expensive, and much more temperamental.

Agreed a resort diver that has a few logged dives will have an idea of how long an AL80 will last at a given depth with a given temperature and an average exertion level. The fact is that few dives stay at a given depth, and then this diver with limited experience may suddenly find themselves under a thermocline or in a stronger current. This causes their exertion level to increase sharply and their consumption of air along with it. These factors are extremely difficult for even a experienced diver to gauge mentally. I think it is very responsible informing these divers that even though they don't have the experience to be masters of gas management there are devices that can accurately do it for them in real time. Not everyone has a AI computer but maybe more would knowing more about them. Not everyone wants a console or wrist AI computer but they should at least understand what advantages and disadvantages up to date versions of these devices exhibit and be able to make a well informed decision regardless of the cost considering the performance and safety issues.

 

[jkramer]

I had a similar occurrence diving rental equipment at Ambergris, Belize. It was obvious that the gauge had stuck at ~2500 psi, since it hadn't moved over several minutes. Luckily my dive buddy was my wife, who I know uses air at about the same rate I do. So, I could complete the dive assuming my air was ~ the same as hers, but of course playing it safe and being up with 750 psi in her tank.

 

[trigfunctions]

A few dives later during a safety stop, my buddy had already gone back up to the boat and we agreed that I would stick with the DM for the remainder of the SS. I started feeling a subtle resistance from my reg. So much that it felt as if I was sucking in my mask. My SPG said I had 500 psi but that couldn't be the case when it was getting harder and harder to breathe... The DM and I were elbow to elbow and I gave him the OOA sign. I never, ever thought I'd use that sign in a real situation.

The DM looked at my SPG, gave it a whack and the needle dropped to 0.

Thanks for posting this, and it sounds like you did a good job keeping your wits about you and buddy breathing.

But - shouldn't you have been on the surface with 500 psi? That's the rule of thumb for most boat dives. Also, if the guage was stuck at 500 psi when the tank was really almost at zero, does that mean you were puttering around for quite a while with the guage reading 500 psi and not noticing that the needle wasn't moving? What was the total dive time and depth profile? Just a couple thoughts.

 

[paradise]

Shouldn't you have been on the surface with 500 psi? That's the rule of thumb for most boat dives. Also, if the guage was stuck at 500 psi when the tank was really almost at zero, does that mean you were puttering around for quite a while with the guage reading 500 psi and not noticing that the needle wasn't moving? What was the total dive time and depth profile? Just a couple thoughts.

We were instructed to ascend and finish the dive when the needle hit 500 psi. But I understand what you're saying. I was in fact puttering around and looking at my gauge but I truly thought that it was because I was doing a heck of a job conserving my air. :small:

Many lessons learned.

 

[scubafanatic]

I was in fact puttering around and looking at my gauge but I truly thought that it was because I was doing a heck of a job conserving my air. :small:

Many lessons learned.

...well, as they say, if it appears too good to be true, it probably is.....

 

[pasley]

Thank you for posting.
During a cruise in the Caribbean (Grand Cayman, Roatan, Belize, and Cozumel) on which I took my own gear at every stop I noticed the rental gear with the copious champaign bubbles coming from everywhere at each stop and was sooooo happy I had brought my own gear. Many other countries have shall we say much looser standards than the USA does.

On my return from my cruise a friend of mine told me about an event he observed years before at one of the places I had been. He saw them use the 2nd stage to unclog a plugged toilet. Then a quick rinse and back on the rental rack. Yuck! So glad I had taken my own gear.

 

[Eff]

On my return from my cruise a friend of mine told me about an event he observed years before at one of the places I had been. He saw them use the 2nd stage to unclog a plugged toilet. Then a quick rinse and back on the rental rack. Yuck! So glad I had taken my own gear.

Holy crap.

That is just... beyond bad.

 

[drbill]

SPGs can not only be faulty, but also inaccurate. Rental gear is often a source for problems if it comes from a shop that does not service the gear regularly. In some countries I've rented gear that failed miserably on a dive... fortunately nothing truly serious. Always a good thing to do a thorough check of any rental gear.

It is interesting that one of the few areas I see redundant gear is with SPGs... with the exception of some diving doubles. Given the occasionally critical nature of an accurate measure of remaining gas supply, I do find this interesting. I dive with redundant computers and tanks, but only one SPG on each.

 

[StuartT]

Thanks for your post. Sounds like you handled the ooa situation very well. I use an AI wireless wrist computer but also have a backup pressure guage in case of computer failure at least I'll know what my remaining air is.