Upside down air?

[andymaher]

I know this is going to sound silly, but why do divers wear their tanks with the valves on top? Firemen wear the valves on the bottom, where they are MUCH easier to reach. Granted, the hose routing is simpler with the valve and first stage up top, but it seems to me that a bottom mounted first stage would facilitate a hose routing similar to the DIR "under the light canister" position, then under the knife, around the back, etc. It also seems that a bottom mounted first stage would be less likely to snag, and easier to clear if it does snag. (and easier to turn on in the event that you forget!) Am I missing something?

[ScubaCollin]

I think it has alot to do with the hoses, Winding them all the way up your body like that every time would be a pain in the ***. The Valve in my opinion would be harder to reach through your legs that a simple reach behind the head.

This is all speculation, I have no clue why it is the way it is for a fact.

[Kim]

I asked the same question a while ago and got a couple of answers. Maybe you'd like to see them:
http://www.scubaboard.com/t53192-.html

[jbd]

I know this has come up in the past and there are some people who dive with the tank "upside down" Typically the protective gear that a fireman wears is much bulkier than that worn by divers and they would be very limited in their ability to reach a valve behind their head.

A search on scubaboard will probaly turn up some more answers.

[Allison Finch]

Yes, the valve would be easier to reach, but the valve would take too much of a beating. You would carry your tanks on the valve all the way to the dive site? You would rest the tank on the valve to put it on? you would slam the valve onto the bench seat when you sit down to doff your gear after the dive? I think not.

[Kim]

Yes, the valve would be easier to reach, but the valve would take too much of a beating. You would carry your tanks on the valve all the way to the dive site? You would rest the tank on the valve to put it on? you would slam the valve onto the bench seat when you sit down to doff your gear after the dive? I think not.

No of course not!!! You'd obviously stand on your head to put your gear on!

[roturner]

I know this is going to sound silly, but why do divers wear their tanks with the valves on top? Firemen wear the valves on the bottom, where they are MUCH easier to reach. Granted, the hose routing is simpler with the valve and first stage up top, but it seems to me that a bottom mounted first stage would facilitate a hose routing similar to the DIR "under the light canister" position, then under the knife, around the back, etc. It also seems that a bottom mounted first stage would be less likely to snag, and easier to clear if it does snag. (and easier to turn on in the event that you forget!) Am I missing something?

Here's my thinking.

Part of it is custom. The older double hose regulators needed the valve to be higher than the mouthpiece or the reg would freeflow. ONce you get started like this it quickly becomes the way you do things....

The second part is conviencience. It's easier to rig it up with valves up because you can just put the tank on the ground. Don't forget scuba tanks are larger and heavier than fire-fighter tanks.... Also the hose routing is easier.

And the third bit is gravity. divers, unlike fire-fighters, lay horizontally and can hang forward to move the valves up higher where they can be reached.

R..

[dsaxe01]

Humm... i always thought that the firefighters tank was upside down first, because of entanglement, and second, because the reg went to the belt, then connected to the mask.

[Northeastwrecks]

I know this is going to sound silly, but why do divers wear their tanks with the valves on top? Firemen wear the valves on the bottom, where they are MUCH easier to reach. Granted, the hose routing is simpler with the valve and first stage up top, but it seems to me that a bottom mounted first stage would facilitate a hose routing similar to the DIR "under the light canister" position, then under the knife, around the back, etc. It also seems that a bottom mounted first stage would be less likely to snag, and easier to clear if it does snag. (and easier to turn on in the event that you forget!) Am I missing something?

1. The hose routing is simpler when the valves are on top.

2. Hitting the valves is not particularly difficult. It just takes practice, proper placement of the tank and a bit of flexibility.

3. I don't need special protective cages (aka potential entanglement hazards) to protect the valves when I don and doff the rig.

In addition, if the valves were on the bottom, I'm not sure how easy it would be to hit the isolator without resorting to a slob knob.

[BigJetDriver]

Folks,

This question comes up every so often. It depends upon where you are when you ask this question.

Commercial divers and European divers wear the cylinders with the valves down a lot. There are various reasons. A search will pull up many older threads on this subject.

Truly it is six of one and a half dozen of another, or chaque a son gout, if you will. (I hope those who actually speak French will pardon the spelling.) The valves down system is as old or older than the valves up system.

Also, despite the emotional freight offered by some (i.e. "slob knob"), no such device is needed to get to the center control, unless other equipment gets in the way, or your joints won't go that far for some physiological reason. In which case, the extension is just a tool to get a job done.

As Mr. Natural always said: "Get the right tool for the job, kids!"