How do divers not realize their air isn't on?

[M DeM]

Try it once - it's part of open water training as I understand it. Turn your air off, and breathe thru your reg, how many breathes till it starts to get some resistance (I suspect different regs "feel" different), you got one breath left at best.

I see many people turn air on to check for pressure then turn off for the boat ride out - they don't do a precheck or a buddy check - it's that simple.

Complacency

Pre check and buddy checks are taught in OW, at virtually every step of advanced training, it's re enforced, it shouldn't happen pure and simple but it does cause we are human.

Advanced training helps one deal with stress, helps one avoid panic - we are taught from the beginning solutions to virtually all problems that can occur but panic wipes that training out and can result in an unfortunate tragedy.

Right - I'm guessing these folks didn't have buddies.

I didn't have that training for OW. Take mask off, yes, but not air off. However, I'm starting with a volunteer dive team at an aquarium, and they said after a few weeks they put you through a "panic test" underwater. I'm interested to see what my reaction to things are!

 

[rhwestfall]

I will admit to finding my air off, but never having entered the water with it that way. I also buy the person who gets to turn it on a drink for my stupidity.... motivation to not repeat it....

 

[scubadada]

meaning, use the regulator (have it in your mouth, test it) before entering the water, right? Is that what "pre-breathing" is?

Take 2, 3, 4 breaths off the regulator while watching the SPG, pressure will go down, to zero, if tank is off. If I turn off my tank, I purge the gas so that the SPG will already be at zero before I would test.

 

[RyanT]

@M DeM, yes bre-breathing means sitting on the boat, taking several breaths off your reg and watching your gauge. If you tank is off you'll get resistance pretty quickly and see your spg needle drop. In which case, you just turn your valve on. Rebreather valves are often easier to reach then open circuit tanks. They are a special beast, however and require an entirely different protocol for ensuring their operation compared to open circuit tanks.

 

[The Chairman]

Complacency kills.

Over weighting kills.

Oversights kill.

You are your own best friend or worst enemy.

I prebreathe my regs three times while looking at my SPG before I splash. If the SPG moves wildly, my air is not all the way on. If a DM gets close to my tank with his paws, I'll prebreathe again. I've had them turn off my tanks and they were indicator valves.

I follow a written check list on my rebreather. If you interrupt me, I start from the beginning. There's nothing down there worth dying for.

 

[RyanT]

As I mentioned, rebreathers are special beasts compared to open circuit. It is entirely possible to be breathing gas, but that gas is not capable of sustaining life (e.g. high CO2 or low O2 levels). In open circuit, it's less of an issue. However, when diving heavy steel doubles, it's not unusual for a diver's gear to be 30+ pounds negative when stepping off the boat. An unprepared diver without some kind of additional flotation can sink quickly.

 

[dmaziuk]

Right - I'm guessing these folks didn't have buddies.

I didn't have that training for OW. Take mask off, yes, but not air off.

Before you step off the boat, inflate your aircell and take a couple of breaths from the reg (pref. both) watching your SPG. If the needle goes down, you air is off. Then hold on to your junk and step off. I'm sure "inflate" and "hold on to your junk" was in OW but I forget if our instructor mentioned the SPG needle or I picked it here on SB or from a DM somelace.

No, we didn't have "air off". That would be a bad idea in an OW course.

 

[M DeM]

As I mentioned, rebreathers are special beasts compared to open circuit. It is entirely possible to be breathing gas, but that gas is not capable of sustaining life (e.g. high CO2 or low O2 levels). In open circuit, it's less of an issue. However, when diving heavy steel doubles, it's not unusual for a diver's gear to be 30+ pounds negative when stepping off the boat. An unprepared diver without some kind of additional flotation can sink quickly.

I see. 30lbs would certainly be tough for me.

@M DeM, yes bre-breathing means sitting on the boat, taking several breaths off your reg and watching your gauge. If you tank is off you'll get resistance pretty quickly and see your spg needle drop. In which case, you just turn your valve on. Rebreather valves are often easier to reach then open circuit tanks. They are a special beast, however and require an entirely different protocol for ensuring their operation compared to open circuit tanks.

I'm going to do that. Thanks. I usually start breathing well before I'm entering the water, but I don't watch the gauge. From now on-- I will.

 

[M DeM]

Before you step off the boat, inflate your aircell and take a couple of breaths from the reg (pref. both) watching your SPG. If the needle goes down, you air is off. Then hold on to your junk and step off. I'm sure "inflate" and "hold on to your junk" was in OW but I forget if our instructor mentioned the SPG needle or I picked it here on SB or from a DM somelace.

No, we didn't have "air off". That would be a bad idea in an OW course.

Yeah, my instructor never mentioned doing a breath test while looking at the gauge. Probably would be a good idea for them to teach that. I know I'll do it from now on in.

 

[RyanT]

Here's another thing, if your valve is "cracked open" just a tiny bit, your reg will likely breathe just fine on the surface. However, your spg needle will swing hard everytime you inhale, so watching your gauge will alert you to that problem.