Going tech, backmount or sidemount doubles?

[FoxHound]

It shouldn't happen that a tech instructor goes anywhere near a student without substantial personal experience, not just in the kit, but in the particular type of diving and conditions to be expected.

Well said, couldn't agree more.

 

[Otto]

Are you diving solo, and if not what are your future tech buddies diving, and what are your long term goals? Before you spend any money on equipment I would see if I could borrow or rent some gear and a vareity of cylinders to find what you need, the HP130 is not the perfect cylinder for every situation. If you are diving with buddies all the time there are some advantages to every one having the same configuration, like as in borrowing dive gear. Best of luck.

 

[Dive-aholic]

The instructor also said that if the student was doing the course sidemount, at least one dive would be conducted in backmount. (1 dive does not develop skills).

I'm curious why the instructor is requiring this. Is this an Intro to Tech course or a decompression course. I can't think of any reason to require a dive be done in backmount, especially if you're not proficient in it. I would also advise you not to take a decompression class in sidemount without first having some experience built up, even after a class.

Also, sidemount diving is not exclusive to cave diving. While it has its origins in cave diving it is not solely done by cave divers and is not a requirement for cave divers. There are plenty of cave divers that backmount.

---------- Post added April 4th, 2012 at 10:19 PM ----------

Do it in back mount.

Sm has some serious drawbacks that people don't like to talk about.

Tanks are heavy? Hit the gym.
Neoprene suit sucks? Get a better suit.
Cant afford doubles? Save your nickels.
Cant get doubles were you're going? Color me skeptical.

The loss of half your gas supply due to a reg failure is a big problem, as is donations, frequent switching, and general lack of consistency between divers.

There is a reason technical divers of yesterday spent considerable time and energy creating the manifold.

Spoken like someone who has little to no experience in sidemount. Your ignorance of sidemount is very clear in your choice of "drawbacks".

---------- Post added April 4th, 2012 at 10:24 PM ----------

I keep seeing gear solutions to lack of skills problems, but haven't seen anything convincing enough to give up that redundancy that a isolator manifold gives you. YMMV.

An isolator still provides a failure point that can cause yyou to lose more gas than a set of independents would. The nice thing about sidemount is you can see your 1st stages and valves and conduct a valve shut down much faster and more efficiently. And you also have the option of feathering your valve, something not easily done in backmount.

 

[darushin]

As Someone who dives both I will tell you it really depends on what you want. They both have their place, and to simply discard one is not a good choice. My suggestion is since you know you want to do Tech look into the NOMAD XT with a doubles adapter. That way you can use the same BC for what ever method you decide.

Daru

 

[PfcAJ]

Rob, you act like a free flow is the only flavor of reg failure. The risk of Losing half your gas is asinine, especially if the dive doesn't require you to take on that additional risk.

Thats a very important thing to consider, as when dives go tits up, all the textbook stuff usually gets shaken up a bit. I prefer to dive a system that gives me the widest range of options across all tthe most common failure modes.

 

[markmantei]

Rob, you act like a free flow is the only flavor of reg failure. The risk of Losing half your gas is asinine, especially if the dive doesn't require you to take on that additional risk.

Thats a very important thing to consider, as when dives go tits up, all the textbook stuff usually gets shaken up a bit. I prefer to dive a system that gives me the widest range of options across all tthe most common failure modes.

The way it was explained to me, and keep in mind I have NEVER dove sidemount or attempted either of these, but...

In the event of a reg failure, the regs can be swapped, as they are accessible (not fun I assume underwater with dry gloves). I would think this would take sufficient time to need to be on a 3rd gas source (stage or team member), also in dire circumstances one could breath directly from the tank valve, although I'm sure this would be in life or death decision time, I bet there is some real danger of lung over-expansion injury without the regulators. Neither options are available in backmount, but then there is the isolator.

 

[PfcAJ]

Swapping regs underwater... is that really what you want to do? Lose an oring and its curtains for you...

With BM, you just switch to your backup reg and have access to ALL your remaining gas. Bingo bango. Keep it simple

 

[Adobo]

The way it was explained to me, and keep in mind I have NEVER dove sidemount or attempted either of these, but...

In the event of a reg failure, the regs can be swapped, as they are accessible (not fun I assume underwater with dry gloves). I would think this would take sufficient time to need to be on a 3rd gas source (stage or team member), also in dire circumstances one could breath directly from the tank valve, although I'm sure this would be in life or death decision time, I bet there is some real danger of lung over-expansion injury without the regulators. Neither options are available in backmount, but then there is the isolator.

Whereas on back mount, all you have to do is shut down the post that has the 1st stage/2nd stage failure or ruptured hose. While breathing from the good reg, you have access to all gas remaining gas. No third gas source needed while you monkey with swapping regs from one tank to another.

The biggest advantage I see with side mount is you can go in smaller cave than you can with back mount. But my question is, how many full cave dives will you need to do before you are bored with all the different places you can go on back mount? Just know that there have been many many cave divers with hundreds and thousands of cave dives that dive back mount exclusively. (Did Sheck Exley ever dive side mount? If not, I wonder how he ever got by without it.)

And certainly for open water technical diving, there aren't really any dives that you can do on side mount that you can't do in back mount.

 

[JamesK]

(Did Sheck Exley ever dive side mount? If not, I wonder how he ever got by without it.)

Yes he did. Not in the form you see today, but he did do it, and no mount.

 

[Teller]

Why cant we just agree that both have their advantages.