My venture into Sidemount.

[Jax]

HUH??

I think he's referring to NetDoc's story at http://www.scubaboard.com/forums/5564864-post372.html.

 

[Kevin Carlisle]

I think he's referring to NetDoc's story at http://www.scubaboard.com/forums/5564864-post372.html.

Ok, then the answer is NO!!! You never use more than 1/3 of your gas in either cylinder, EVER!!

 

[ucfdiver]

It was asked earlier why we keep the pressure so close on tanks, let me relate an experience from this last weekend.

I did two dives in Ginnie Springs this past weekend. The first dive was way cool and we penetrated about 1,000' back (almost to the Maple Leaf). I started with 3600 across both cylinders and when the dive was turned I was at 2600 and 2400 respectively. I did get a little sloppy with my switches on the way back which resulted in there being 450 psi difference at one point. I finished the dive with both cylinders within a 100 psi.

On the second dive we got back around 1100' on Hill 400. Since I started with just a bit under 3300 in each cylinder, my turn was 2200, We turned just as I reached 2200 on one with 2400 in the other. I had no problem with keeping within 300 during the dive, and on the way out I was treated to the "Eye Bypass" which is a squiggly little bypass that you have to think and slink your way through. It was fun and I believe I was within 200 psi at the end of the dive.

On the bottom of the steps, the three of us were unhooking our bottles and such when my left first stage let loose. WHHHHHHHHHHHHHOOOOSHHHHHHHHHHHHHHHHH. The HP seat/valve had failed and I quickly turned off the air. As one of my buddies commented: "Talk about perfect timing for a failure!" Wow. What if that had happened while I was still in there? Holy Schnieke! I would have been left with only one tank to breathe off of.

Now imagine if I had only drained the right tank (used 2/3s of it or 1/3 total) and this happened when I was 1100' back? If I was diving solo I might have died. Yes, it takes a lot less gas to exit Ginnie then to penetrate, but I would have only half the gas that I came in on. Even with a buddy, I would have severely limited my options as to how I would exit. Keeping the tanks within a few hundred PSI maintains my redundancy. That's a good thing.

Another failure where BM would have more gas. Wish those who financially gain from SM (instructors who really push it mainly) would stop pretending it's safer from a gas management standpoint.

 

[Jax]

Another failure where BM would have more gas. Wish those who financially gain from SM (instructors who really push it mainly) would stop pretending it's safer from a gas management standpoint.

Okay, I've puzzled over this a while . . . what do you mean? How would a BM have more gas?

 

[The Chairman]

Okay, I've puzzled over this a while . . . what do you mean? How would a BM have more gas?

It's pretty typical. When someone does not like a particular solution, they assign greed to those who choose to use it. It's not warranted and only serves to polarize any useful discussions. Pity that!

I know of no side mount instructor who claims it "safer". They do suggest that bubble checking and isolating a massive leak is quicker, easier and more certain. In fact, there were a number of restrictions where reaching back mount knobs would be impossible. My hands are next to my Sidemount valves all the time. I love it.

 

[ucfdiver]

It's pretty typical. When someone does not like a particular solution, they assign greed to those who choose to use it. It's not warranted and only serves to polarize any useful discussions. Pity that!

I know of no side mount instructor who claims it "safer". They do suggest that bubble checking and isolating a massive leak is quicker, easier and more certain. In fact, there were a number of restrictions where reaching back mount knobs would be impossible. My hands are next to my Sidemount valves all the time. I love it.

I'm just saying it seems that we have a lot of "medical reasons" where no one can dive BM recently that didn't' exist several years ago. Seems odd to me. Now we're all acting like an isolator is an evil device with no statistical proof, when in all reality almost every gear failure that actually happens is better fixed in BM.

 

[Jax]

I'm just saying it seems that we have a lot of "medical reasons" where no one can dive BM recently that didn't' exist several years ago. Seems odd to me.

James, you are begging the question here . . . you are assuming the medical reasons didn't exist, perhaps because you haven't heard of it, and using that assumption to make an oddity of it.

I submit that the medical reasons existed, and propose that fewer people went to further their diving skills into the arenas which required more tanks because they couldn't / shouldn't carry the weight, or were not comfortable launching their BM in the water and gearing up in the water.

Those who transferred from BM to SM 'carried the water' to others who simply didn't know about sidemount, and the word spread. Now, with articles like just showed up in Divers Alert mag, more and more may choose to go sidemount if for no other reason, they can work with the weight.

I can tell you from experience with the Army, the VA, and medical screening boards that there are a LOT of Infantry soldiers that pound the ground with 60-80 lb rucksacks on their back for 20+ years, and they are and will continue to pay for that the rest of their lives.

Future sidemount divers, for sure!

 

[Kevin Carlisle]

James its simple. If you don't like it, don't use it. I hated backmount, I won't dive it agvain. I wasn't any safer in BM and nobody can explain how I supposedly was. SM isn't for everyone, in the wrong hands I agree it would be dangerous, but at the same time those people shouldn't be diving BM either.

 

[ucfdiver]

James its simple. If you don't like it, don't use it. I hated backmount, I won't dive it agvain. I wasn't any safer in BM and nobody can explain how I supposedly was. SM isn't for everyone, in the wrong hands I agree it would be dangerous, but at the same time those people shouldn't be diving BM either.

I don't think I said I didn't want to use it. Obviously there's lots of caves where I just have to. I just think an open discussion should focus on real pro/con's rather than this hypothetical completely OOA situation that's never happened in cave diving (except when using high ENDs).

 

[Jax]

I don't think I said I didn't want to use it. Obviously there's lots of caves where I just have to. I just think an open discussion should focus on real pro/con's rather than this hypothetical completely OOA situation that's never happened in cave diving (except when using high ENDs).

Psssssst . . . James, this thread is for those of us venturing into sidemount.

In other words, we've made the decision, and this is our occasionally comical foray into the culture. However, you might start another thread on your discussion - I imagine that thread would be quite spirited and interesting!