Octopus second-stage: over shoulder or under arm?

[CuzzA]

Note: if you're short like me, 40" can be too long for the under arm primary to be completely streamlined and it'll find its way past and over your elbow. I imagine the opposite problem applies if you're larger/taller than average. If you're interested in that set-up, try to measure with a piece of string or something under your arm for the best hose length, or see if you can try it on someplace

A 90° elbow will usually help that. Not one of those multi direction elbows, but a true 90 will force the hose down. A swivel turret first stage on the correct LP output will help too. I also nixed hose protectors which aside from being a good practice for reducing corrosion on the hose fitting, it also allows for better hose routing. This is an older pic showing my setup. I no longer have that SPG hose. My rec. open water rig now has just two hoses. Gotta love an Air2 with wireless AI. You literally can't get more streamlined than that unless you oral inflate and ditch the octo, the latter would only make sense if you were strictly a solo diver.

 

[Diver-Drex]

This is a great learning video. I personally never had any issues with my Air2 and i kind of want to go back to it. However, in this video, I saw the other person had an Octo...why didn't the one person whose gauge was leaking use that? But I will say everyone was super calm and I think this should be shown to others.

Why would a diver with a leaking spg switch off of their primary reg? They should stay on their primary, use the gas they still have available and then switch to shared air after that supply is run down.

 

[DBPacific]

A 90° elbow will usually help that. Not one of those multi direction elbows, but a true 90 will force the hose down. A swivel turret first stage on the correct LP output will help too. I also nixed hose protectors which aside from being a good practice for reducing corrosion on the hose fitting, it also allows for better hose routing. This is an older pic showing my setup. I no longer have that SPG hose. My rec. open water rig now has just two hoses. Gotta love an Air2 with wireless AI. You literally can't get more streamlined than that unless you oral inflate and ditch the octo, the latter would only make sense if you were strictly a solo diver.

View attachment 531017

I have an elbow. Mine's a small 360 but I keep it at a 90-70 degree angle. True 90 degree elbows kept shoving in my face and are a nuisance. I'm just short and have short arms. The 40" hose is manageable if you're my size, but it does escape under my arm at times.

 

[GameChanger]

Are you saying that a diver grabbed your reg out of your mouth in an OOA at 100ft?

Though I've seen this said many times on threads that this can happen, but if that is what you are saying, this is the first I've seen of someone saying it actually happened to them.

I am indeed. I also admit that I/We are very lucky to be alive! I should note that I am estimating the depth because we did not have a depth gauge. We were diving off Scripps Canyon in La Jolla, CA. (San Diego).
This was in the early 70's and we had J-Valve tanks with no SPG's. The only "dive instrument" we had between us was a dive watch that we used to time the dive. I kicked-in the J-valve "reserve" on our rapid ascent (another lesson learned...). My dive buddy inadvertently pushed the j-valve to the down position and had already exhausted his "reserve" air supply.

 

[Scuba-74]

Why would a diver with a leaking spg switch off of their primary reg? They should stay on their primary, use the gas they still have available and then switch to shared air after that supply is run down.

I would imagine a leaking SPG would display inaccurate (lower than actual) readings, and also would be quite difficult to read.

 

[Bob DBF]

Imagine that was a night dive with 10' visibility.

That's when I figure it would happen, between my luck and average viz around here being 15 feet or so.

I can say though from a real-deal OOA experience with a buddy at ~100 ft that the OOA diver will grab/go for the closest regulator they can see. In most cases that will be YOUR primary. They can forget their training and switch to survival instinct in a heartbeat.

I've been mugged twice, but for the most part air shares went well. Except for one of the muggings, all were before we were using an SPG, and on a k-valve there is no reserve.

With a diver that practices air sharing, it's a non event. One has to get used to not having to have a reg in their mouth and understand how long one can actually be without air. More time in the water without tanks helps.

This is a great learning video. I personally never had any issues with my Air2 and i kind of want to go back to it. However, in this video, I saw the other person had an Octo...why didn't the one person whose gauge was leaking use that? But I will say everyone was super calm and I think this should be shown to others.

For some folks on the board Air 2 goes in the same bin as split fins, jacket BC's, and SpareAir. It's about percieved possible issues and personal better solutions (i.e. My gear is better).

As @AfterDark mentioned, it was probably a training video. I concur because of the actual buddy breathing being done, I don't see that much any more.


Bob

 

[The Chairman]

Are you saying that a diver grabbed your reg out of your mouth in an OOA at 100ft?

I've had that happen before on the Speigel. I didn't even know the guy, and he wasn't from my boat. He was mad when we got on the 'wrong boat'. It was right for me.

 

[uncfnp]

I was doing a pool dive last night and when setting-up the kit I was wondering if it's okay for the octo to go over your shoulder as oppose to under your arm? My reasoning is that if your first-stage is at about shoulder height to me it makes sense to go straight over your shoulder then this way if it gets grabbed and pulled in an emergency your arm doesn't impede the pulling action or tensioning from the hose-straightening that will happen when pulled? Just a thought really. Cheers.

Chris. Are you asking if you can just route your existing octo hose over your shoulder rather than under the arm?

If so, of course you can do what you like but I don’t recommend it. The standard octo hose is much too long for this and the loop would create a hazard. And putting your octo on a shorter hose is not a good option, it will be too short for an air share. Unless you do completely should up your reg and go with the streamline configuration and then the “octo” become your primary and you do a primary donate.

 

[Diver-Drex]

I would imaging a leaking SPG would display inaccurate (lower than actual) readings, and also would be quite difficult to read.

Yes, the reading may be off. But switching off your primary doesn’t solve that. And there is no reason to just ‘give up’ on that gas. HP leaks are ‘slow’ and there could be a lot of usable gas in that cylinder.

Maintain contact with your buddy and make sure they know what’s going on. Have them verify their octo is operational (should have done this already) and use as much of your gas as you can.

 

[Scuba-74]

Yes, the reading may be off. But switching off your primary doesn’t solve that. And there is no reason to just ‘give up’ on that gas. HP leaks are ‘slow’ and there could be a lot of usable gas in that cylinder.

Switching off your primary doesn’t solve that, but with SPG being effectively useless, you won't know when you are about to run out of gas until you literally run out of gas. I don't know if that's a good strategy, but I see the point that there is no reason to switch off right away, because the buddy may not have all that much gas left either.