7 replies to this topic

[BubbleBoy]

There is no substitute for real life experience. However, one of the things I do to improve my diving safety is imagine problematic diving scenarios that I never thought of before, and then try to solve them in advance. That way, if I ever encounter such a situation in diving, I won’t be as likely to panic and screw up.

I realize there is never a universal solution to such problems, because, it always depends so much on circumstance, i.e., diving conditions, gear configurations, etc. Still, I think it is a useful exercise, because, it brings to light the many different variables that can come into play. Plus, it’s a lot more fun to experience these things in your office chair than while actually diving.

So here goes.

You are diving on a wreck at 120’ with a single tank and reg. You do not have a redundant breathing system, but, you are diving with a buddy with a similar setup.

At the end of your dive, with just enough gas in either tank for the two of you to make it to the surface, you suddenly feel a sharp tug on your rig that pulls you back hard. You look down and discover that your sleek little mini gauge pod has slipped through a crack in the wreck hull and become lodged in something behind the crack. Try as you might, you can’t wedge it loose. You can’t even see the gauge pod, just your HP hose coming out of the narrow crack. YOU ARE HOOKED.

What do you do now?

[scubafanatic]

There is no substitute for real life experience. However, one of the things I do to improve my diving safety is imagine problematic diving scenarios that I never thought of before, and then try to solve them in advance. That way, if I ever encounter such a situation in diving, I won’t be as likely to panic and screw up.

I realize there is never a universal solution to such problems, because, it always depends so much on circumstance, i.e., diving conditions, gear configurations, etc. Still, I think it is a useful exercise, because, it brings to light the many different variables that can come into play. Plus, it’s a lot more fun to experience these things in your office chair than while actually diving.

So here goes.

You are diving on a wreck at 120’ with a single tank and reg. You do not have a redundant breathing system, but, you are diving with a buddy with a similar setup.

At the end of your dive, with just enough gas in either tank for the two of you to make it to the surface, you suddenly feel a sharp tug on your rig that pulls you back hard. You look down and discover that your sleek little mini gauge pod has slipped through a crack in the wreck hull and become lodged in something behind the crack. Try as you might, you can’t wedge it loose. You can’t even see the gauge pod, just your HP hose coming out of the narrow crack. YOU ARE HOOKED.

What do you do now?

...well, if you'd kept your SPG ( I use those small Halcyon SPG's) clipped closely to your BCD, as I do, this never would have happened.
...I'm unclear as to whether you mean to say that the buddy team is using the 'rule-of-thirds' whereby you've both just turned the dive when the highest gas consumption diver has signaled he/she has just consumed 1/3 of his/her gas......or if you mean the team has just reached the point in the dive where each diver only has enough gas in their tank to supply one diver back to the surface, namely themselves ?
..... I'll assume they're using the rule-of-thirds.
I'd likely consider simply cutting the HP hose and leaving the SPG behind....... the gas flow/loss from an HP port is fairly small, and the 'victim' diver can use his/her air supply for a long as possible before having to share gas.
...this is VERY different than what would be possible with a severed LP hose.......in this case, gas loss would be total in 1 - 2 min, in round numbers...depending on tank pressure.

Karl

[BubbleBoy]

...I'm unclear as to whether you mean to say that the buddy team is using the 'rule-of-thirds' whereby you've both just turned the dive when the highest gas consumption diver has signaled he/she has just consumed 1/3 of his/her gas......or if you mean the team has just reached the point in the dive where each diver only has enough gas in their tank to supply one diver back to the surface, namely themselves ?

My thinking was similar to the rule of thirds. I'm assuming the other diver has enough gas for both to ascend.
In this situation, I tend to agree with you about cutting the hose. I must admit my first instinct was to ditch my rig and surface with buddy. Not a bad solution. It works. It’s the kind of thing they taught us in dive training. But the more I thought about it, cutting the HP hose has advantages, such as:

- It’s the quickest solution. Time is precious, particularly at depth.

- I still get to breath some of the remaining gas in my tank before the leaking hose exhausts it. At least I can make part of the ascent before I have to start buddy breathing. Breathing the remaining gas first could turn out to be a life saving decision if anything else goes wrong.

- It retains the possibility of surfacing on my own gas if I can find a way to quickly plug the severed hose. This may not be as difficult as it sounds. I once experimented (in my garage) with a free flowing HP hose connected to a tank that had about 1000 psi in it. It was relatively easy to stop the flow by jamming the tip of the pencil from my writing slate into it. It only took a few pounds of force to hold the pencil in. I think you could do the same thing with an LP hose too if you had the right plug. They flow more when broken, because, the inner diameter of the tube is bigger. But the pressure inside is also lower, so the force on the plug would be about the same.

- I can still make use my own buoyancy control system during ascent; the part of the dive when buoyancy management is most critical. That way neither diver is required to manage a less familiar rescue ascent, or make massive buoyancy adjustments associated with ditching my gear.

- Last, and definitely least, I only lose my gauge pod instead of my entire rig. Hey, I paid a lot of money for that stuff!


Thoughts…. comments…. is anyone still willing to go diving with me?

[ScubaDadMiami]

I can't see waiting until the last second to start my ascent. So, this would not likely happen. You should always have sufficient reserve gas for these kinds of situations.

For example, on deep dives, I always leave an extra three minutes for me to get the anchor off of the wreck, starting my ascent. If things take a little longer than planned, I get out within my outside range of the dive plan. If things go faster, than I have only missed a minute or two of getting so close to the line.

I can't imagine how you could get into a situation like this where you couldn't back up, slide out the gauge from the reverse of how you got it in there, and then just remove it.

[Cold_H2O]

Since you are diving to 120' on a single I am hoping you are using nothing smaller than a 120 tank.
I can't imagine going to 120' on a single tank ~ unless you are not planning on spending much time at depth.

I also can't imagine getting any gear stuck ~ You shouldn't have any danglies.
I have been known to swim behind a diver with danglies and stop and hold on to the dangling gear.
I know.. I am evil.
I usually only get to do it once before the diver learns to keep his gear out of the muck.
The look on their faces when they make that sudden stop is worth it.
I just have to keep from laughing too hard. My air consumption sucks when I laugh too much.

If you can't get your gauge free ~ I think cutting your hose and plugging it is your best option.
Leaving all your gear behind ~ Is not imho a good idea.

Next dive ~ keep your gauges close.. clipped to your BC or BP.
Watch your air ~ head to shallower depths before you have just enough air to reach the surface.

[Capn Jack]

mi dos psi - I am assuming you're diving a recreational profile - i.e. "no deco"

Concur on cutting the hp line - just make real sure you know which one you're cutting, have a hold on the inboard side of the cut, and don't slice yourself in your enthusiasm.

I'd ascend pretty smartly to 60' at 60 fpm and then slow down to 30 assuming I was on track with gas consumption. I think that 30 fpm all the way is a good plan when you have plenty of gas, but in this case I'd sacrifice the first rough half of my pressure differential to try to preserve my 15' safety stop and a nice, slow transition from there to the surface.

LMAO about grabbing dangly things... I'll have to try that.

[fala]

This reminds of a book I read - Diver Down by Micheal Ange. The entire books deals with diving fatalities - what went wrong, why, and how they could have been avoided. I read this after I first got my Open Water and only had a few dives, it really opened my dives to how you can get in trouble easily if you don't know what you're doing or take things for granted.