Tried to Kill Myself but Failed!

[Scuba_tacoma]

I can think of many situations where it would be very dangerous to attempt to ascend from 80 feet. Have you ever done it yourself, or is this something you just assume based on reading things? I am serious, have you practiced multiple free ascent from this depth without any problems?

Obviously, the answer is no and I would not recommend anyone should practice free ascents. I am making that judgment based on the no need for decompression i.e. recreational diving, along with the idea that you would like have some air source. 80 ft is less than 30yrds, for comparison olympic swimming pools are 165 feet long, 80ft is not that deep.

I don't worry too much about running "out" of air at 80 feet. If you are calm and you run the pressure way down, it is not that hard to add a puff of air to the BC and breathe shallowly as you ascend at a moderate rate. Once it gets a little hard to inhale at depth, in reality there is quite a bit more usable air in a full size scuba tank if you are calm enough to sip it.

But what if you are for example, catching lobsters.. and you have 400-700 psi at 80 feet and lurch forward under a ledge to snatch a lobster and you rip the LP hose as it exits the first stage? (Or the yoke first stage is dislodged from the tank due to the low pressure and force of impact allowing the valve face oring to extrude)

I doubt that I move toward more lobster at even 700 psi, I would be on my way to the boat. To play along with the scenario, we have all probably pushed limits.

How hard are you lurching forward? I don't use my tank as a battering ram on the ledge. I have never heard of or seen someone cutting their hoses on a ledge much less knocking off their first stage. I have seen hoses break once pressurized but not just spontaneous rupture.

I suppose a shark or an eel could decide to bite it?

What if (at the time) you have a bag of heavy lobsters on your harness, what if you are deliberately 5-7 lbs negatively buoyant at the time (so you can more effectively work the bottom)? Now you exit the hole, and your air supply is going to be completely exhausted in maybe 20 seconds? If you don't immediately get air in the BC, very few people are going to be strong enough to swim to the surface.

On an accent of this nature, you would start dumping weight in proportion to the speed you need to ascend

That is one very simple scenario, that I can envision that would make a pony bottle very useful.

I know lots of people look at the risks and decide a pony bottle is not worth the trouble, but to imply that there are no situations where it would be extremely beneficial (or needed) is pretty short sighted.

I did not imply there are no situations where it wouldn't be beneficial. In fact, if any of the situations you listed happened then most divers would prefer a pony bottle. However, the bad situations with the pony bottle are more likely than your examples. I don't think you would instantly be drowned or have an embolism from an ascent from the situation.

My stance is the chances of a diver needing the pony bottle is significantly lower than the chances for problems the pony bottle has and will cause. If the O.P. would not have figured out his issues then he would have completed an ascent or worse, due to the pony bottle.

 

[FishWatcher747]

I did not imply there are no situations where it wouldn't be beneficial. In fact, if any of the situations you listed happened then most divers would prefer a pony bottle. However, the bad situations with the pony bottle are more likely than your examples. I don't think you would instantly be drowned or have an embolism from an ascent from the situation.

My stance is the chances of a diver needing the pony bottle is significantly lower than the chances for problems the pony bottle has and will cause. If the O.P. would not have figured out his issues then he would have completed an ascent or worse, due to the pony bottle.

Your argument does not apply to side slung Pony bottles. In a slung Pony bottle with the regulator bungied to the Pony there is no confusion about what regulator one is breathing from.

 

[johndiver999]

I did not imply there are no situations where it wouldn't be beneficial. In fact, if any of the situations....

Ok but this is what you said previously:

At 80ft, and not planning any deco then no need for a pony.

 

[John C. Ratliff]

I have practiced an ascent without air from 80 feet. To do this, I started in a 16 foot deep diving pool (platform diving), and did a doff of all my scuba equipment. I then simulated an out-of-air situation by turning off the air, exhaling and trying to inhale without success. I then commenced to swim horizontally, and up, until I had covered an estimated 80 feet (I started out on one side of the pool along the wall, and went diagonally across a 60 foot (20 yard) wide pool to the other side. About half way (after ascending 8 or so feet) I started to blow out excess air (yes, I had some), then surfaced. After a short recovery period, I repeated the process, and swam back to my unit and conducted a “don” drill, getting the entire unit on with that one breath from 80 feet away. Well, it actually was pretty easy to do.

On an actual working dive, in the mid-1970s, I ran out of air at about 40 feet, second dive of the day on the same tank, an 80 cubic foot steel tank. Well, I still had a number of photos I wanted to take, so I swam over to one of the two other divers I was working with, who were dredging for clam bed research, and indicated I needed to buddy breath (no octopus regulators at that time). I took three breaths, backed off and snapped a few photos with my Nikonos, then came back for more buddy breathing. I did that three times, if my memory is correct, then did a free ascent to the boat to end the dive. That, to me, was not a problem.

SeaRat

 

[Gone for diving]

Had a yoke valve o-ring extrude during a dive today in 85 feet

Checked the Oring, re-tightened the yoke and did another dive 10 minutes later.

Seems yoke was not tighten properly.
If an oring extrudes at those pressures
The oring will be bad and cannot be re used. So there must have been a big enough gap to push the oring through, without destroying it.

 

[johndiver999]

Seems yoke was not tighten properly.
If an oring extrudes at those pressures
The oring will be bad and cannot be re used. So there must have been a big enough gap to push the oring through, without destroying it.

Yes I must have been sloppy with tightening the yoke. About the oring; Sorry, but you are mistaken. I stuffed the oring back in the groove, tighten the hell out of the yoke and went diving. LOL. I did have it replaced at the shop when they filled it.

 

[MB NZ]

Sounds like the prelude for a good, old fashioned DIN vs yoke argument since the pony discussion is at stalemate

 

[narcosisjunky315]

You should cut a piece out of the corner of your regulator mouthpiece that was you know what reg is what. I did that on my sidemount tank set up. Makes things so much easier to remember.

Glad you didn’t get hurt!

 

[JuLe]

Sounds like the prelude for a good, old fashioned DIN vs yoke argument since the pony discussion is at stalemate

I was wondering why on earth anyone would use yoke but didn't want to ask..

 

[happy-diver]

Mate what's that thing they say where we live

If you leave the gate unlocked don't go chasing the wombats after they have run off
into the bush because you had so many locks it took too long to figure out the keys

You make an excellent, if obscurious point.

Mate it's clear to me ha ha ha, that they're doing a Munchausens on their diving and their gear
and their minds so they can come in here and talk about it then all the like minded folks follow
these guys in with the same or similar ideas, with everyone wearing themselves out completely
disproportionately with stories on the solution, rather than wisely concentrating on prevention

So someone does something dumb, then spends the bulk of their time, unnecessarily
attempting to dumb proof their gear when the gear didn't do the dumb the diver did

You should know what to do in case but not spend mega hours planning and thinking
whereby it interferes and eats into the time that would be better spent on, prevention

Tell everyone else to shut up, get into your divers head know your gear and go diving

So that's concentrate for the last five minutes before the dive without talking to all the
social experience people visualise the dive in your head without your gear blowing up

But really all it really is is just don't run out of air, and don't dive dumb, with the dumb

Yeah I know!