Anti-snag valve-down tank mounting?

[Javik]

Is there some reason generic recreational scuba diving has standardized on a valve-up position for air cylinders, with hoses sticking out all over the place on the 1st stage? It's just easiest to do things that way?

Valve up seems to be a lousy way to do things if you are at risk of snagging underwater objects and you can't see what is behind you..

It seems like it would make much more sense for the valves to point downward, with a shoulder ring like on propane tanks so it can be set down upside down without resting on the valve, and have hoses that run up the sides of the tank(s) to the usual location, held in place alongside the tank.

Now the only thing behind you is the bottom of the tank, which is much less likely to snag on anything as you swim forward.

This also makes it far easier to turn the tank valve on or off behind you, since an upside-down tank valve will be approximately at hip level.

 

[RainPilot]

One reason, I suspect, is that with the current setup the regulator / hose setup is tank-length agnostic. Tall S80, short S63 etc etc all handled by the same rig. Also, gearing up on a boat would be a lot harder if you had to fiddle beneath a tank to get kitted up i think. Carrying the tank would require some sort of handle on top as well, the valve is awfully convenient for that...

Generally, If the valve is positioned correctly, there should be little to no chance of it hitting anything for 99% of dives.

Another thought, since the valve part is the heaviest underwater, a valve down setup would progressively make horizontal trim harder as the tank emptied. Not a deal breaker but something to consider.

 

[Diver0001]

You mean like this guy? His name is Nigel. Nigel..... Hewitt if I recall. About 15 years ago he got into quite a discussion with, among others, the DIR crowd because of this configuration. The short story is that it works and in his case it was necessary to do something along these lines because he doesn't have normal mobility in his arms. Notice that the tanks still have boots on them. This is a practicality that was necessary for setting the tanks down upright for things like filling. Personally I think the boots could be taken off. IIRC the crux of the discussion went like this:

Nigel: Hey guys I started wearing my doubles upside down so I can get at the valves with my gibbled arms
DIR guys: You are going to die, you should stop diving, you're an idiot, do not disseminate the devil's work like this online.
Nigel: But it works, In fact it works very well.
DIR guys: You are going to die. Everyone who reads your posts is going to die. Looking at those pictures will make you die. If you touch water even the fish will die
Nigel: But it works, In fact it woks very well.

etc etc.

In defense of the DIR crowd they had some valid concerns about the configuration and in further defense, the online rhetoric has calmed down by about 90% since this discussion was waged.

Nevertheless, in my opinion, it was these kinds of attitudes that kept us from exploring variations of the Hogarthian configuration that could have lead to some improvements. This is only one such idea.

The main disadvantage of the rig, as I recall (as I said, it was a while ago) was that all the hoses needed to be cut to custom lengths and there were some routing complications. There were also some legitimate concerns about the cage forming a potential snag hazard of its own that would need to be addressed if you really wanted to reconfigure along these lines.

On a side note, look at the following picture. Firefighters ALL wear their tanks upside down for reasons of being able to get to the valve easily and keeping hoses and snag hazards to an absoute minimum. Look at that picture and tell me that it isn't thing of beauty. With some minor modifications I'd wear that diving! Wouldn't you?

 

[CuzzA]

Is there some reason generic recreational scuba diving has standardized on a valve-up position for air cylinders, with hoses sticking out all over the place on the 1st stage? It's just easiest to do things that way?

Valve up seems to be a lousy way to do things if you are at risk of snagging underwater objects and you can't see what is behind you..

It seems like it would make much more sense for the valves to point downward, with a shoulder ring like on propane tanks so it can be set down upside down without resting on the valve, and have hoses that run up the sides of the tank(s) to the usual location, held in place alongside the tank.

Now the only thing behind you is the bottom of the tank, which is much less likely to snag on anything as you swim forward.

This also makes it far easier to turn the tank valve on or off behind you, since an upside-down tank valve will be approximately at hip level.

So, a couple things you'll find and a couple things you can and, IMO, should do.

First, there's nothing "generic" about a traditional recreational rig. While I understand where you're coming from as a new diver, you have to put this into perspective. 10's of thousands of dives are being conducted every year and the valve up poses no more entanglement hazard than the valve down. If you were to be so incredible unlucky to have something snag your valve and first stage, well, you're diving with a cutting device (2 is 1, knife, line cutter and/or EMT shears) and a buddy, right? You stay calm and fix the problem.

Second, valve control. Barring a disability, you should be able to reach the tank valve. Bottom line. Practice until you're proficient.

Third, I don't know if you've done any boat diving yet, but do you want to be on a pitching boat with a now unstable rig and trying to flip your rig upside down? Tanks want to tip over as is even with a flat boot, they'll want to tip even more with the commonly sold valve stands. Are you going to rig every one of your tanks this way? What about when you rent tanks? Are you going to continue to uninstall and reinstall the valve stand every time you dive a new tank. I promise you that will get old and you'll be stuck with that configuration since you sized your hoses for that setup. Which beings me to my next point.

Once your first stage and hoses are on the tank they shield a lot of the entanglement hazard. If you're in good trim and your head up, your head is likely to hit whatever entanglement hazard is present first. Which, there isn't much of an entanglement hazard in OW. I'd say wrecks present the highest possible risk of entanglement. Staying on the subject of hoses... If you route your hose right and size their length right, you can literally achieve hose routing that is barely visible.

For example, I dive what I consider a modified streamlined open water setup and it took some patience to get my hose lengths just right. My inflator routes tight over my left should down to my Air2 which is held close to my chest with a magnet. My naked SPG is tight to my body under my left arm and clipped to a lowered left shoulder d ring. My primary is on a 40" hose routed under my right arm and comes up to my mouth on a 90 degree elbow. You could look at me in the water from any angle and you'd be hard pressed to find any daylight between my hoses and body. For most, instead of the Air2 in the streamlined setup, you would put your backup second stage on a short ~22" hose over your right shoulder on a bungeed necklace. See the illustration below. Isn't that pretty?

Everyone has the right to dive whatever rig configuration works for them, personally, I think your entanglement concern is unfounded with any substantial risk and the hose issues could be solved with better routing and proper lengths.

 

[Patoux01]

On a side note, look at the following picture. Firefighters ALL wear their tanks upside down for reasons of being able to get to the valve easily and keeping hoses and snag hazards to an absoute minimum. Look at that picture and tell me that it isn't thing of beauty. With some minor modifications I'd wear that diving! Wouldn't you?

AFAIK, the main reason they're upside down is so that you don't smash the reg/valve on let's say a staircase or a door frame. It also allows them to keep the center of gravity as low as possible, we don't care about either of those.




The weight distribution also changes wildly when you go from a normal twinset to inverted twins. Also if you're going to have a manifold, that valve gets tricky to close (or so I heard).

Go ahead and try it if you want, but I personally don't see any use to inverting tanks. (but then again, sidemount makes almost all the issues you mentionned a non-issue)

 

[KevinNM]

This was from an article by a UK GUE tech instructor on reaching valves. Note that inverted rigs are much more common in the UK. The various pieces you need to protect and run inverted rigs are also easier to get in the UK.

Reaching your valves
"This is one of those TRUTH moments, where you have the priveledge of sharing something which many people seems to struggle with but is an undeniable fact. Are you ready? Here we go. Inverted cylinders are easier to shutdown. Sorry!

"There’s so many pros and cons of both ways that I am not going to get into it, but the fact remains that from a perspective of shut downs, inverting is the way forwards, so to speak. Many people adopt inverted rigs for this very reason. It doesn’t appeal to me, but then I can do a shutdown. The DIR mob claim that everyone can do a shutdown if their rig is properly configured and they are trained properly in how to trim and weight themselves etc. Well, for the Non-DIR crowd, there really is some truth in this I’m afraid. For the DIR crowd, it is “some” truth, and not the whole of the truth. Some people simply do not have the mobility in their joints and require another solution. This section is in here just to recognise and remind you that the contents are what worked for me, and what I learnt on the way. You may have a pre-existing condition that means inverting is the only way to do it, and if so, go for it! Actually, if you just fancy having inverted cylinders, go for it."

 

[Rich Keller]

Commercial divers usually wear the tanks upside down so the valve is easier to reach and the valve & reg is in a more protected position. Many sport divers are already using ridiculously long hoses as it is so turning the tank upside down shouldn't be a problem. Though most would rather do it the hard way I guess so they have another so called skill to practice. Do they have a C-card for turning on tank valves yet?

 

[CuzzA]

That looks like a bigger snag hazard than just a reg and valve. In fact it would really suck to snag mono, etc. on that behind your lower back. You'll be doffing your rig to get free.

I'll concede easier valve control, but there's only one practical reason to have valve control... dropping in with your tank off. Didn't you check before you dove?

And again, if someone showed up on my boat with that, I'll be wearing closed shoes and keep my camera trained on them when they're trying to gear up.

 

[RainPilot]

That looks like a bigger snag hazard than just a reg and valve. In fact it would really suck to snag mono, etc. on that behind your lower back. You'll be doffing your rig to get free.

I'll concede easier valve control, but there's only one practical reason to have valve control... dropping in with your tank off. Didn't you check before you dove?

And again, if someone showed up on my boat with that, I'll be wearing closed shoes and keep my camera trained on them when they're trying to gear up.
View attachment 381864

Valve control is pretty important when diving twins with a ceiling as well (deco or solid) when isolating a manifold can be the difference between a thumbed dive and a chamber ride or worse.

 

[Basking Ridge Diver]

AFAIK, the main reason they're upside down is so that you don't smash the reg/valve on let's say a staircase or a door frame. It also allows them to keep the center of gravity as low as possible, we don't care about either of those.
The weight distribution also changes wildly when you go from a normal twinset to inverted twins. Also if you're going to have a manifold, that valve gets tricky to close (or so I heard).
Go ahead and try it if you want, but I personally don't see any use to inverting tanks. (but then again, sidemount makes almost all the issues you mentionned a non-issue)

The valve is on the bottom because it helps the valve from catching on things while you are crawling around in the dark and have a potential for collapse (in the ceiling the HVAC ducts are full of wires and will drop on a collapse), protects the high pressure hose that comes off the valve (keeps the hose tight to the body and in the harness), and it's easier to turn on and off (we don't turn the tanks on until last minute, most of the time I'm in the building before turning it on.)
These are the basic reasons the valve is on the bottom.