Doing it Ridiculous

[Snowbear]

**final warning **

Calling each other names, whether it be "Stroke," "meathead," "jackass," "jerk" or any other name is prohibited. Continuing to do so will result in posting privileges being suspended.

 

[CIBDiving]

You know, You're takeing ALL the fun outa this thread!! You'll also notice I've been mistieriously quiet and well behaved.

 

[Snowbear]

You can have all the fun you want without resorting to personal attacks and name calling.

 

[shiro85]

Mark - the point is if there is no air left in the tank there is nothing to use.

Sure, but it also helps to know your gear and to use that knowledge to take the best course of action.

For example, a full AL80 with *no* regulator attached takes roughly 2 minutes for it to completely drain:

http://www.undercurrent.org/UCnow/articles/SpareAir9902.shtml

Since a 'burst o ring' is a more constricted airflow path its going to take longer than this to drain. At only 50% constriction, it would take twice as long - - assume that that lets us account for less than full tanks - - ie, a tank that has its failure when its only half full (1500psi) will still take roughly 2 minutes to drain.

A Rec OW ascent from 90fsw up to the surface in 2 minutes with a remaining air supply is not an ESA suicide run. In fact, in the "old days" before we had safety stops and reduced the 60ft/min ascent rates, a completely normal ascent would have only taken 90 seconds.

So if my buddy's not immediately there, my recourse would be proceed up without delay. Sure, if I can get the valve partially closed on the way, great, but it can wait until I'm to at least safety stop depths before pausing to work on it and to try to get in a short safety stop.

In a free flow situation you can get air through the flow, turn it off, ascend a bit blowing your bubbles to keep your air passage open, turn it on and repeat.

True, but with such a procedure, you're adding a lot of complexity, which reduces its probability of successful execution.

It also merely swaps risks - - the on/off/blow/go bit effectively increases your risk of an Embolism for what gain? A reduced ascent rate to reduce DCS risk.

But for an Rec OW dive, which is more dangerous: a DCS hit or an Air Embolism?

Answer: the DCS hit is significantly more survivable. As such, increasing your Embolism risk just to lower an already low DCS risk sounds like the wrong risk trade-off to make.

 

[TCDiver1]

even if he wasnt "DIR", he was still an egotistical jackass
somthing about diving just brings out that kind of stuff in people, has nothing to do with DIR

Yup, divers have liked to argue about minutiae long before the internet existed. The internet just makes it easier and more convenient to get in ones cyber-face.

Oh how i long for the days of the K-valve vs J-valve debates.

 

[Mike Veitch]

Oh how i long for the days of the K-valve vs J-valve debates.

See, just like the players, you Dead Things fans are all old! :11:

 

[MikeFerrara]

Sure, but it also helps to know your gear and to use that knowledge to take the best course of action.

For example, a full AL80 with *no* regulator attached takes roughly 2 minutes for it to completely drain:

http://www.undercurrent.org/UCnow/articles/SpareAir9902.shtml

Since a 'burst o ring' is a more constricted airflow path its going to take longer than this to drain. At only 50% constriction, it would take twice as long - - assume that that lets us account for less than full tanks - - ie, a tank that has its failure when its only half full (1500psi) will still take roughly 2 minutes to drain.

A Rec OW ascent from 90fsw up to the surface in 2 minutes with a remaining air supply is not an ESA suicide run. In fact, in the "old days" before we had safety stops and reduced the 60ft/min ascent rates, a completely normal ascent would have only taken 90 seconds.

So if my buddy's not immediately there, my recourse would be proceed up without delay. Sure, if I can get the valve partially closed on the way, great, but it can wait until I'm to at least safety stop depths before pausing to work on it and to try to get in a short safety stop.



True, but with such a procedure, you're adding a lot of complexity, which reduces its probability of successful execution.

It also merely swaps risks - - the on/off/blow/go bit effectively increases your risk of an Embolism for what gain? A reduced ascent rate to reduce DCS risk.

But for an Rec OW dive, which is more dangerous: a DCS hit or an Air Embolism?

Answer: the DCS hit is significantly more survivable. As such, increasing your Embolism risk just to lower an already low DCS risk sounds like the wrong risk trade-off to make.

That's one way of looking at it and it might make sense for some. If I have a reg free flow, though, I'll switch to another source and shut it down in the hopes it'll thaw (if it's due to freezing). At 90 ft, I likely already have that other source on my back in the form of doubles or an h-valve but if not and I need to ascend from any depth on my own gas from any depth, I'll feather the valve before rushing my ascent. Which is worse, dcs or embolism? I don't want either one, thanks anyway. From shallow depths with plenty of gas left, I'll just breath the free flow because I have plenty to get up and why bother? I'll still reach back and shut it down at the surface though. From deeper, like the 90 ft we're talking about? I'll use the valve. I'm not adding any risk because I can do it easily. Complex? Says who?

Having solid basic skills, seeing to common sense equipment configuration issues like being able to reach your valves, good gas management and some redundancy when it makes sense (like deep dives) all give the diver more options and might avoid having to rush to the surface leaving a buddy behind.

Free flows happen in cold and/or deep water. I've seen more divers hurt or nearly hurt around here because of not being able to handle them when they happen than any other cause. Some agencies teach it but they usually teach it kneeling on the bottom which is useless and too many get into trouble because they can't manage it midwater. Being able to reach your valves is only part of it. The first step is to be able to maintain control and be functional (midwater where we should be diving) with all the bubbles and that's where most divers lose it. I've had to direct traffic for the ambulances too many times.

In any case, wearing your tank where you have no chance of reaching the valve completely eliminates the option which makes no sense. It's also just another of the MANY things you'll need to clean up and relearn if you continue to advance in your diving. Even if you will never turn a valve off as a single tank/single outlet valve diver, you may just need to turn it on some time. Just put the tank where it needs to be from the start and be able to reach the valve. Be able to do it midwater while holding your depth and keeping track of anything else you need to be aware of. There's absolutely NO disadvantage to being able to do it and several advantages even if we can argue about just what they are.

 

[Kim]

For example, a full AL80 with *no* regulator attached takes roughly 2 minutes for it to completely drain:

Probably true with a full tank. How often, and for how long, do you have a full tank during a dive? How many rec divers start ascents from 90ft with 3000psi? I've seen people start up from that depth with less than 1000psi. With such a failure how much more gas will you lose before you realize what happened and start a 60ft/min ascent?
By your calculation 1000psi will empty in roughly 40 seconds. It sounds to me like roughly a 120ft/min ascent. You could even be another 10, 20, or 30 ft deeper and still be doing a rec dive.

I don't like the sound of that math. I'll keep my valve where I can reach it thanks!

 

[D1V3R]

Yup, divers have liked to argue about minutiae long before the internet existed. The internet just makes it easier and more convenient to get in ones cyber-face.

Oh how i long for the days of the K-valve vs J-valve debates.

lol, i took my last j-valve and an old steel 72 and made a mailox out of it

 

[headhunter]

At the urging of a few members, I've just taken a look at this thread. I did not read the entire 25 pages, but read enough to see why some members feel that things may have gotten a little out of hand.

Snowbear is absolutely right in asking people to lay off of the personal attacks. Here is the paragraph from the TOS that we're talking about:

No post should exceed a "work-place friendly" rating (defined). Profane, insulting or mean spirited language is simply not allowed here. Neither is any sort of harassment or bullying. Threats of any sort are grounds for immediate banishment. While the debates may wax passionate, there is no need to revert to personal attacks. If you feel that you have been attacked, please do not retaliate and instead use the "report this post to a moderator" link at the bottom of the post to notify us. No trolling or flaming of any sort is allowed in any section of the board! Posts advocating or condoning illegal activity are also not allowed on SB.

I think this paragraph speaks for itself. We don't want to keep anyone from having fun. Ensuring discussions remain within the TOS is actually for the purpose of keeping it fun. If a discussion cannot remain civil then those who are stirring things up will wind up with a vacation from ScubaBoard for the benefit of those who like our civil environment.

Just keep in mind that a discussion can get very passionate and heated without becoming uncivil.

Christian
ScubaBoard Advisor