Drop your weights or not...

[jmasin]

but do not allow yourself to be 100 ft down and 50 yards from your backup air. Dive with a pony, a good buddy, and/or stay on his butt - and check his spg personally often.

Don, Agree 100%.

I think most of this thread assumes we've already gotten ourselves in deep, pardon the pun.

I'm exceptionally good about buddy-ing. If they aren't close they aren't useful in an emergency (nor am I for them). I stay close. Less so on a 20' shore dive with 100ft viz, but otherwise I'm typically two strong kicks from my bud. I check my spg frequently and query my bud frequently too.

I can't even imagine, barring equipment failure or an already existing emergency prevent ascent, being OOA at depth.

 

[DandyDon]

Re: and query my bud frequently too

I look at his spg.

 

[Amphiprion]

Dropping weight wasn't really emphasized to me during my open water class. Perhaps this was because I was an in shape but generally skinny 13 year old boy diving in the tropics. In salt water I only needed 4 lbs and could easily tread no air in the bc and the weight belt attached with a full tank.

Years later I did my intro to tech where we avoided weight belts if at all possible or wore them underneath the crotch strap of a bp/w as fighting ascent on a deco stop was far worse than needing to use a SMB to help maintain buoyancy at a deco stop in the event of a wing failure.

Later I did my OW rescue class (out of order, I know). Here we were taught that part of self rescue is ditching weights. Frankly I was a bit horrified after coming from a tech class. The instructor also pointed out that most people found dead on the bottom still have their weights on. I asked the instructor if he thought the proximate cause of these deaths was failure to ditch or drowning from a heart attack. I was told that he was teaching the course material, but that I was probably correct.

My own philosophy is to never carry ditchable weight and weight myself so that I am neutral with empty tanks on the surface. I also always carry redundant buoyancy in the form of a dual bladder or a drysuit or a SMB, depending on the situation.

 

[xyrandomyx]

There are some mixed opinions on that, perhaps deserving of a separate thread - maybe in Dive Medicine. There is a risk of Laryngospasm but passed out - it would still be best to drown and/or embolized (word?) on the surface if at all. I saw a diver plucked from the water unconscious and embolized once. Scary. He was from our boat but we could not get to him downcurrent at the time but another grabbed him and sped him to shore for a waiting ambulance. We had a lunch break and an afternoon trip scheduled and I wondered if any of us would go, if I would, since we kinda thot he was a gonner - but by the time to board, we heard he was arguing with the hospital on whether he had to spend the night or not. Of course he did as Dry drowning and other risks were still in play.

I'm still on last resort, but it was finally suggested in the Accident thread that spawned this one to remove weights and hold them on an emergency ascent, in case you passed out - then you would ascend. Better idea.

OK, my question about whether your airways would stay open if you were to pass out was really out of curiosity. It makes sense that you'd probably be better off at the surface either way.

Removing and holding onto weights doesn't seem like a bad idea to me. I'm wondering if there are some situations where having both hands free might not be a better idea, though. I don't know.

 

[DandyDon]

OK, my question about whether your airways would stay open if you were to pass out was really out of curiosity. It makes sense that you'd probably be better off at the surface either way.

Removing and holding onto weights doesn't seem like a bad idea to me. I'm wondering if there are some situations where having both hands free might not be a better idea, though. I don't know.

I am bad about following my camera, which is part of what caused my Cesa screw up in 2009, but I keep it secured to my wrist so I can turn it loose without losing it - and did. I also have an orange float on the wrist strap; my new one floats, but it is still black.

One hand on a weight pocket/belt, one on the BC inflator/deflator, teeth securely on my reg - I can't think of anything more important - except maybe watching your computer, and I wear one on my wrist. I do carry a spare weight pocket on trips too.

It'd be difficult to arrange, but I wonder if more divers need to take a slung tank & reg with 500# down to 50 ft and breath it to OOA to experience the feeling...?

 

[diver 85]

yes-------if you need more(immediate) buoyancy.....Of course, we had the CO2 cartridges in our old(1st)BCs for that too.....After about 7 or 8 years, I fired off both my wife & I's & just left them in there used...

 

[boulderjohn]

Bleeb already did a nice job covering the key points. I just want to make sure it was not missed and then add a little more.

What if you realize you are OOA right at the end of a good, deep exhalation at 100 feet (with no buddy around). A CESA is effectively impossible. If you ascend at 30 feet per minute, you might pass out before you get to a depth at which you could get a meaningful breath out of your tank.

Your lungs still retain quite a bit of air with O2 in them. Your blood retains O2 in it. If you ascend from 100 feet after a full exhalation, you will not only have enough O2 in your system to make it to the depth at which you will get more air from your tank without passing out (which isn't that far), you will probably make it to the surface.

If you experience an out of air at depth on your last exhale, and for whatever reason your buddy isn't within reach, (shame on you) keep the regulator in your mouth. As you ascend you may be able to get a breath or two off the tank as the small amount of air expands in the tank.

This isn't actually what happens. The air inside your tank is in an inflexible container and is not affected by changes in pressure around you. The problem is that your lungs do not have the ability to inhale against the pressure of the water around you unless the air is coming out of the tank through the regulator at a pressure higher than the pressure of the water around you. Once the pressure in the tank drops below a certain PSI, the regulator can no longer give the air to you at enough pressure. Once you ascend--and it won't be that far--the drop in the water pressure around you will allow the regulator to give you air at sufficient pressure for you to inhale.

Here is what I think is a problem in training. What Bleeb and I have said is not part of normal instruction. I add it and emphasize it, but I don't personally know anyone else who does. When we practice the CESA, we are supposed to fail students who inhale before they reach the prescribed distance on one exhale. This has two problems:
1. We effectively teach students that if they can't make it to the surface on one exhale, they are screwed. If they run into the situation in real life, they will probably think "I can't make it exhaling all the way," and they may be inclined to hold their breath.
2. When we fail them on the exercise if they take a breath a few feet from the finish line, we fail them for doing the right thing. I can't think of any other place in education in which a student is given a failing grade for doing exactly what should be done.

Finally, I asked earlier when we draw the line between dropping weights and not dropping weights. I bet a lot of people would think OOA at 100 feet after exhaling might be a good time to drop the weights.

 

[eponym]

It'd be difficult to arrange, but I wonder if more divers need to take a slung tank & reg with 500# down to 50 ft and breath it to OOA to experience the feeling?

You can safely approximate the sensation of running close to empty, and you don't even have to get in the water. Just remove the first stage dust cap and breathe off the second stage (with the reg set not connected to a tank). WOB (work of breathing) is much greater than when breathing off a tank.

I have OWD students do this in in the hope that, should they stop monitoring their gas for some reason, the increasing WOB just might remind them to check their gauge. raying:

-Bryan

 

[xyrandomyx]

@boulderjohn I was definitely told in my OW class that I should keep the reg in my mouth in case of an OOA situation because I would be very likely to get another breath out of it in shallower water. I'm also pretty sure it's somewhere in the PADI OW book (but, of course, that's not quite the same as having it reinforced through the practical CESA exercise).

 

[boulderjohn]

@boulderjohn I was definitely told in my OW class that I should keep the reg in my mouth in case of an OOA situation because I would be very likely to get another breath out of it in shallower water. I'm also pretty sure it's somewhere in the PADI OW book (but, of course, that's not quite the same as having it reinforced through the practical CESA exercise).

I'm glad you were taught that. I don't have an OW book with me, but I would be surprised to find it in there.

With PADI, CESA instruction is different from any other skill. In all other skills, there is a lot of latitude with how you can do things, and descriptions are a bit vague. That is intentional, because there is more than one way to perform these skills effectively. With CESA, we are given very precise instructions. For the OW performance, we are given a script of points that MUST be covered in the briefing. There is no mention of the fact that the tank will be able to deliver air at shallower depths in our instructions for teaching this.