Doubles vs Sidemount

[PfcAJ]

If you blow an isolator o-ring, you've got 1 or 2 more o-rings to go (depending on the make of your isolator). They're static o-rings, too.

While I'm sure its "possible", I've never seen or heard of an isolator failing in that way. All the other 'failures' out there I have either seen personally or heard about 2nd or at least 3rd hand. They might be more rare than even tank neck o-rings failures.

I know a guy who has dropped 2 sets of 104s out of a moving truck on two separate occasions. The isolator was bent into a lazy S shape, valve knobs were sheared off, DIN outlets deformed, but nothing leaked.

 

[billgraham]

BUT . . . it turns out that there were some real issues to face. To begin with, it's relatively difficult to put together or find a sidemount setup that works well in cold water with steel tanks. It can be done, but most rigs are optimized for cave diving, which isn't done in 45 degree salt water. I've also done a little bit of diving with sidemount buddies. Except for Curt Bowen and Ben Martinez, they've all been much slower to be ready to dive than those of us who just throw on a set of doubles. It's clear that, if you have your gear set up just right and you dive it often, you can get pretty fast (and I was diving on a boat with Curt, who quietly and efficiently geared himself up just as fast as anybody else there, including the single tank people.) But when you're new at it, it's very time consuming.

So right now, I'm still diving BM, on the theory that almost all dives can be done that way, and I know the system, and have all the kinks worked out of it already.

We spent a lot of time about ten years ago figuring out how to make our sidemount rigs work for cold water wreck diving with steel tanks so ask me if you have any questions. Most of the problems revolve around the fact that it's a dexterity intensive rig and you've got lobster claw gloves on, and we came up with some neat stuff to make it more workable.

The gear up time is longer in the beginning, like any new rig. At this point, I'm fast in the OC sidemount rig and almost as fast as the OC sidemount guys in my CCR sidemount rig, but that took a lot of dives.

As for Ben, he can just "do stuff". Give him anything and he'll figure it out, really fast.

Agreed. What does that Sorensen guy know anyway?

Yeah man, you're going to let some hockey player from Oregon tell you what to do? *laughing

 

[DevonDiver]

I've had a leaking isolator valve. Nothing drastic... just bubbles. Was noticed on the surface and resolved before diving - so no idea how close it would have been to a more catastrophic failure.

 

[PfcAJ]

Where was the leak? Make of the isolator, please? Rental or personally owned? Service interval? This is the 1st one of these I've heard of that wasn't at a fill station (which is an 'ok' place for leaks to occur, imo. Better there than in the water).

 

[DevonDiver]

It was a rental. Don't know, or can't recall any specifics.

 

[billgraham]

I used to crew on a dive boat for a while and I saw several sets of doubles go pitching off the bench onto the diamond plate, after which the manifolds leaked and were hissing gas. I'd say "I'm not touching that, they are your tanks, you take care of it!"

 

[PfcAJ]

I think the face-seal type (OMS) ones are more prone to leaking from impact than the barrel o-ring deals.

If you're swimming or scootering fast enough to break a manifold, somethin' aint right!

 

[billgraham]

I think the face-seal type (OMS) ones are more prone to leaking from impact than the barrel o-ring deals.

If you're swimming or scootering fast enough to break a manifold, somethin' aint right!

Yup, I'd be more worried about knocking myself out cold. Now there's a drawback of sidemount--you definitely need a helmet!

 

[JamesK]

Yup, I'd be more worried about knocking myself out cold. Now there's a drawback of sidemount--you definitely need a helmet!

Yep. Got mine.

 

[TLRRHOBO]

I think its just easy for side mount, and much safer. Ie: Valve under your arm-pit or behind your head. So much easier to switch air regulate free flow and see any leaks instantly. I'm sold on side mount. How many (Dumb divers) died from jumping in to the water with valves off, and couldn't under stress and emergency situation reach behind there head to figure out which valve to open!

Its a no brainer, easy access to your air source quickly. Why dont they have valves upside down like on firefighters Scott pack or on some rebreather's. Why make it harder to get air when you need it most and without being a Yoga instructor.

TLRRHOBO
LONG ISLAND