Tank orientation

[Akimbo]

I have preferred inverted bottles for years. I was working in the North Sea when the UK and Scandinavia was more receptive to Valve-Down configurations then in the US and continental Europe. My first in-water experience was the AGA Divator 324s in the 1970s (aside from rebreathers), currently Interspiro. Of course it has been the standard for firefighting and mine safety for as long as I can remember. Here are images of that rig:



Here are photos of my latest attempt at protectors for small valve-down doubles:



I also like valve-down singles, but have concentrated on doubles to support Progressive Equalization and redundancy requirements for solo diving specified by most agencies. Here is an underwater image of the double Faber HP-72 rig.

Photo by Chuck Davis

The only commercially available valve-down protectors I am aware are made by Custom Divers - Protectors & Lift Bars in the UK.

 

[Nemrod]

Uh, Nemrod, you know that the phoenix nozzle was invented as a way to modernize the aqua-lung right? You got yours through Vintage Double Hose? That's where I got the parts for the DW Stream Air I dive on occasion. No Phoenix, I have a J valve and a wrist mounted depth gauge. The system your diving is a mashup of the old beauty and the new safety.

Uh, the Phoenix is a first stage only. Yes, I have a Phoenix conversion, number JAMES-006. Is there a point to the question? It does not modernize anything other than adding a LP and HP source. The first stage components remain the same and as you know, the Conshelf, Titan and Legend all share the same basic first stage as the original Royal Aqua Master. And, we were able to utilize the hookah port for low pressure and a banjo bolt for high pressure or attach the spg to the tank port long before there was a Phoenix.

the Aqua-Lung first came out they were primitive as all get out. You had to check your air and calculate how much time you could be down and then stick to a profile. you had to buddy breathe by shoving the mouthpiece at your buddy and hope he didn't panic, which he often did. When you ran out of air you activated your J valve and swam up, assuming that a stray bump didn't activate it during the dive sometime. Maybe you wore a Mae West for buoyancy, maybe you just swam down and swam back up again. Or you weighted yourself to be negative and were could tell your tank got low because you were floating instead of sinking.

I was taught and was open water certified between 1966 and 1968 using double hose regulators and have owned a Mistral from that time, the one I certified on, still have it, still dive it. I disagree with your primitive statement as it is really incorrect, different but not primitive. I am fully cognizant of the days when we (including me) relied on time and depth and SAC rates to estimate bottom time, planning our dives and timing them and using a J valve reserve. Why, is that supposed to be difficult? Mae West?, No, I did not have anything but sometimes we used thee USD/Voit CO2 floats or vests. There were no BCs in use or even existence perhaps save for the Fenzy type units. So, yes, I swam down, swam around and then swam back up and we also, swam out there and swam back more often than not. And we probably had to hike uphill ten miles to get there. Why, is that supposed to be difficult?

first and second stage rigs make diving a lot safer hands down. Now, do they force the diver to be more in tune with his environment, becoming Cousteau's "manfish"? I don't think so. that's why I enjoy diving my double hose, it keeps me on my toes. Plus I enjoy explaining what it is to divers who stare at me.

Again, we can agree to disagree as I do not agree with your safety concern. If you can point to any statistics showing that double hose regulators are less reliable or more dangerous I will be glad to entertain a change of mind. And if you are going to quote me, let's add that safety IS overrated and in fact is a fabrication of the modern mind.

, is the Octo bungied around your neck? Why is that?

Uh, yes it is, that is my octopus for sharing air. It is on a slip knot. Surprisingly, apparently, many do not understand that there have been necklaced second stages since the advent of the single hose regulator. A slip knot releases the regulator just as cleanly as any store bought octo holder and a necklaced second stage keeps it cleanly tucked away just as it did in 1968.

Of course, when I am solo, I do not carry a regulator for sharing air, if I feel I need redundancy then I was full redundancy and go to dual regulators or a pony or some other fully independent system.

N

 

[DaleC]

Which is better, driving on the right or left hand side of the road?

Oddly, people in North America may answer right, and point to the fact that cars all come equipped with steering wheels on the "correct" side. People in Japan would say the left - look, all the road signs are pointing that way.

Tank orientation is a lot like that. Originally both were used but like the Beta vs VHS, PC vs Mac wars, one won out as far as mass production was concerned, though pure practicality may not have been the primary motivator. And like those wars, claiming valve up is superior may come back to bite some in the a$$ down the road when recreational rebreathers become the norm... or mechanical gills.

All the hose lengths you need for inverted tanks can be ordered online for no more cost than standard hoses. I found HP 80's to be short enough to invert, putting the valves near the hips without extending the butt too far up the back.

Some double hoses can also be used with inverted tanks if one chest mounts the reg, which was done quite often by hookah divers in the past. You can even by a reproduction harness from Simon for it today.

Also, I use a 5' hose on my primary which can be routed and donated exactly the same way from either the valve up or valve down position. The distance from mid chest is the same from your hip or shoulder so the hose length doesn't need to change.

 

[Akimbo]

Dale, I see it more like one is free (nothing/valve up) and the other costs the price of a protector. “Good enough for most people” wins the majority of divers. Especially since very few even think about it. Just because it is widely available and less expensive does not make it functionally equal or better.

 

[cbristow23]

Avenger,

Some on this thread have addressed the issue of the SCUBA tank orientation, but not the SCBA tank you wear as a firefighter / EMT or other confined space entry team member. With those setups, especially in a rescue / firefighting application, there is a much higher chance of something falling on your head / back / shoulders during the performance of your duties. This led to the 'upside down' configuration of the gear for firefighting / rescue operations.

-C-

 

[Guba]

I'll agree to a point. Another factor was the other gear worn with the firefighter's SCBA. The helmets of the day (and usually even to this day) had drop bills on the back of the helmet. This prevented debris and water from going down the firefighter's collar. The SCBA was mounted lower and first stage down to keep from interfering with the movements of the firefigher's head.

 

[DaleC]

Dale, I see it more like one is free (nothing/valve up) and the other costs the price of a protector. “Good enough for most people” wins the majority of divers. Especially since very few even think about it. Just because it is widely available and less expensive does not make it functionally equal or better.

One you have to think a bit about, and one you don't. I enjoy thinking so it isn't a problem with me.

One must also not forget the incredible power of conformity, which many people will not challenge. Some will even go so far as to expend an inordinate amount of energy combating anyone else who even suggests doing so; pulling out such reasoning as:

Expense
Difficulty
Danger to ones self
Danger to others

 

[Glenn08]

The length of the tank is an important factor. I wear my twin 50's valve down. I use a Selpak manifold that puts one valve and 1st stage at each hand easily. But my 72 is too long to comfortably wear valve down. The valve end of the tank is the heavy end. You will notice a difference in how the tank sits on your back. Instead of long hoses I have a short interconnect hose from the 1st stage to a 'T' at my shoulder. Take a look at sidemount also to get an easy reach to the tank valve.