Scuba Diving Videos Cutting a Divers Hose Scuba Videos
The urban legends surrounding cut hoses are legion. N
The urban legends surrounding cut hoses are legion. N
Pony thoughts (I know prob beaten to death)
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seaducer
Contributor
Kind of goes to my point don't you think? In less than 10 feet of water with a full tank time to breathing becomes difficult was 1 minute, tank dry in 2. Now if you are at 80 feet with say...1000 PSI? I am not so good at math but a third less air at about 3x the pressure and I am going to say it will take considerably less time to empty your tank.
Less time than it takes to surface safely even without a stop, and if you are a SOB maybe even less time than it takes to get to your buddy.
On the bright side, freeflows in anything above 50 degrees are rare as long as your gear is properly maintained.
I am not saying pony bottles are right for everyone, or every situation. But I think they have a place.
captain
Contributor
Kind of goes to my point don't you think? In less than 10 feet of water with a full tank time to breathing becomes difficult was 1 minute, tank dry in 2. Now if you are at 80 feet with say...1000 PSI? I am not so good at math but a third less air at about 3x the pressure and I am going to say it will take considerably less time to empty your tank.
Less time than it takes to surface safely even without a stop, and if you are a SOB maybe even less time than it takes to get to your buddy.QUOTE]
Not quite the case. Once the hose is cut or the second stage is freeflowing the 1st stage reduction valve is basicly wide open trying to maintain IP but can't. The flow is then limited by the internal restrictions of the regulator so no matter if it is 10' or 100' the flow restriction will not change and since the 1 stage reduction valve is already wide open there is no way the flow rate (cubic feet per minute) can increase. Actually flow rate will be slightly less at 100' than at 10' because at 100' the differential pressure between tank pressure and ambient is smaller than it is at 10'. So time wise there would be no sugnificant difference in time between 10' and 100'.
dumpsterDiver
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Today, I was diving with my 9-yr old son who I REQUIRE to wear a pony bottle. Since he weighs only 65 lbs, his 63 cu-ft aluminum is pretty heavy for him. The only practical pony for him is a 6 cu-ft tank.
Saying that a small pony is dangerous is ridiculous! We were practicing scuba unit removal replacement in open water and he got his primary second stage all tangled in his shoulder strap and it pulled out of his mouth. Apparently I was not very attentive and failed to notice he was having more than the typical issues. I tend to let him work smaller problems out for himself.
As I watched him struggle for about a minute with the tank half on, the snorkel trapped back under his bc and his mask filling with water, I noticed that he had switched over to his pony bottle reg some time earlier. I quickly decided it was time to help him, but I was very happy to see that his first instinct is self-rescue and he was able to immediately got to an independent air source when he experienced problems.
I explained today, that next time he has a problem that requires use of the emergency pony supply, he needs to let me know, but I feel much better knowing that he already has the instincts to go to the pony if he needs to. I am quite sure he could make it to the surface with the small pony if he had an out of air problem at depth.
IMO, the pony was not responsible for helping your son. Your son was ok because he got a working second stage, he was not OOA. That could have been putting the primary back in, going to his backup (octo), or getting one from a buddy. To me that is different than having an emergency OOA at depth and having to go to a pony because you had no other option.
The fact that you let your 9 year old struggle with this and didn't notice he had no reg in his mouth is another story.
People who want to use a pony for redudancy owe it to themselves to look at the type of diving they will be doing (depth, time, conditions, etc.) and figure out how much gas they will need to get them out of a worse case senario.
Buying a pony because you feel you need one, and then picking one because it is the lightest or smallest does no one any favors if it does not carry enough gas to get you safely to the surface.
dumpsterDiver
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First, the point of my post was that he already has the instincts to go to the pony if there is a problem. To me, that means he has sufficient training/skills to use it in a real emergency.
Second, he didn't have a regulator out of his mouth... He made the switch so quick that I aparently didn't notice for like 30 seconds, at which time I notice the thing in his mouth wasn't his primary.
I agree, I should have been more attentive.
To me a pony is NOT for a worst case scenario.. There are many scenarios that are simply unsurvivable.
The pony is to handle the more likely scenarios, which do not involve entanglement, simultaneously running out of air etc. etc.
Somewhere there is a balance between convienence and safety. Maybe a 6 does not cut it for some people, but I saw a guy on wednesday using a steel 100 and a 40 cu-ft pony in 80 feet of water and he really looked retarded to me. I can assure you, he would have been safer with a 13 cu-ft tank as he tried to negotiate the ladder on a relatively small boat in 5-6foot seas in a 25 kt wind.
Whatever the senario, in my opinion, if you are going to carry one I think it is a good idea to base the size on how much gas you need to get safely back to the surface from the furthest point of your dive. If someone wants to use it for other reasons, be my guest, but wouldn't it be good if it worked in a worse case senario too? I didn't see anyone talking about multiple simultaneous failures.
Whatever. I am not here to be a defender of the retarded
I am saying, like I said before, that a pony (if you choose to carry one) should be based on how much gas you need, not for a concern over how you look.
And what do you call your primary gas bottle and regs? That's not inert? But a pony is? C'mon Rick, that's just a plain dumb comment. We all trust inert pieces of gear that we hope will work every time we get in the water. Having a backup just aint so bad.
Kind of goes to my point don't you think? In less than 10 feet of water with a full tank time to breathing becomes difficult was 1 minute, tank dry in 2. Now if you are at 80 feet with say...1000 PSI? I am not so good at math but a third less air at about 3x the pressure and I am going to say it will take considerably less time to empty your tank.
Less time than it takes to surface safely even without a stop, and if you are a SOB maybe even less time than it takes to get to your buddy.QUOTE]
Not quite the case. Once the hose is cut or the second stage is freeflowing the 1st stage reduction valve is basicly wide open trying to maintain IP but can't. The flow is then limited by the internal restrictions of the regulator so no matter if it is 10' or 100' the flow restriction will not change and since the 1 stage reduction valve is already wide open there is no way the flow rate (cubic feet per minute) can increase. Actually flow rate will be slightly less at 100' than at 10' because at 100' the differential pressure between tank pressure and ambient is smaller than it is at 10'. So time wise there would be no sugnificant difference in time between 10' and 100'.
Thanks for pointing that out. Most fail to realize that a wide open free flow on an LP hose is not going to increase in volume with depth. If it takes X time at the surface then it will be approx X time at 90 feet.
N
You're taking the comment out of context (or I am not explaining myself well). Of course we all are trusting our lives to the equipment as soon as we descend, no matter how many backups or buddies you do or do not have.
What I'm saying is, my buddy's gas in his mouth is currently working perfectly when I need it. There is no question it is the right gas. If he hands me the reg in his mouth, then we have 2 people now working on getting a working reg with the right gas into my mouth. The odds of something going wrong (assuming a well trained and practiced buddy) is about zero. But a pony bottle is supposed to be left on. Is the bottle still full? Is it the right gas? Will I successfully deploy it? Will it function properly? Is there enough gas for me to make my escape? Maybe the answer is, "yes" to all these questions. All I am saying is that I'd RATHER trust my well trained buddy with guaranteed correct gas from a reg that is working and a second brain to help me out.
If you think that trusting a working reg with the right gas from a helpful, well trained buddy is dumb, then I am perfectly alright with being in disagreement with you.
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