Sidemount with 50% and 100% mix

Hi all,

Similar to an existing thread on sidemount and deco tanks, I'd like some suggestions on how people setup 4 tank sidmount? Mainly the regulator hose length / configuration etc on the 4th tank, tried googling to no avail.

At the moment I'm comfortable with 3 tanks (2 primary and 1 50% mix). A bit about my current setups with the unmodified SMS 100.

Left side primary bottle (12L Steel): BC inflate hose, regulator hose around back of neck
Left side 50% bottle (80cf AL clipped off below primary): regulator hose around back of neck
Right side primary bottle (12L Steel): Drysuit inflate hose, 7 foot regulator hose across front of chest and around neck

I'm comfortable with this setup and would probably want to avoid changing if possible.

Wanted to add a 100% mix into the setup, most likely I would get another 80cf AL, anyone would suggest the 40cf AL may be a better option for 100%?

From various youtube videos of crazy 6 tank sidemouts, I should add this 4th bottle to my right side? But I have been told by someone to keep all deco bottles on the left? Is this practice mainly for BM people? It's going to be very busy on the left if I have 3 bottles on that side. Not to mention I could be off balance too.

If the right side is the correct spot for the 100% mix, what will be the hose routing? I want to avoid using left handed regs / 90 degree swivles etc. Should it go across the chest again like the current primary right bottle?

Any photos of regulators / setups is also greatly appreciated.


Thanks heaps in advance.

Your setup sounds very similar to mine.
I typically use a 40 of 100% O2 on my right side. Would need to be a monster dive to require more O2 than that! I normally use a left handed reg but it also works using a regular reg on a 40" hose,put reg across chest and then around back of neck in the normal way.

I think all deco bottles on the left is a DIR thing and originates from concerns about trapping the long hose (backmount). Obviously check your seven foot hose can be deployed after clipping the O2.

Thanks ianr33. Makes sense, I think it'll be a LONG time till I get good enough to need 80cf worth of 100%. According to calculations I'd still be ok for a 2 dive day with a 40cf. Less bulk and weight, sounds good.

Probably going to test the across the chest and around neck method. Good point about still being able to deploy the 7ft hose when the 100% is in use, will test that out too. Tho I don't see how that's possible with "ease" when the O2 hose sits "on top" of the 7ft. Any tips on achieving this without a left hand reg?

I personally don't see the 7ft hose being much of an issue. Stage the 100% just like you would your 50 but on the right side, when you unstow the hose just pull out enough to breathe off the hose comfortably. I wouldn't go with a shorter hose because what happens if you need to buddy breathe the tank......and that is why I don't thing you have to worry about the 7ft hose being trapped.....its going to be clipped off by the time you are switched to the 100%, and you are going to donate what you are breathing so that pretty well takes the long hose out of the equation. Not to mention that if your buddy loses his 100%, unless the dive went really pear shaped, they will still have access to back gas in the form of the bungged reg around their neck until you are ready to share deco gas.

I just find 80's more comfortable in the water than 40's, though most 40's I have used have been Catalinas which makes a big difference apparently. Minor point: 80's always rack better than 40's as well.

---------- Post Merged at 07:13 AM ---------- Previous Post was at 07:13 AM ----------

I just find 80's more comfortable in the water than 40's, though most 40's I have used have been Catalinas which makes a big difference apparently. Minor point: 80's always rack better than 40's as well.

As noted above, the 'all bottles on the left' issue in back mount is primarily to prevent trapping the long hose.

In side mount, I prefer to keep the load a bit better balanced and to keep the profile a bit flatter. On a trimix dive for example, where I may have 18/45 in the primary tanks, 32% in an 80 cu ft travel gas/first deco gas stage and 80% or 100% in a 40 cu ft deco bottle, I'll clip the stage on the left and (if I don't plan to drop it soon in a cave) clip the AL 40 on the right.

The critical issue is that no matter where you carry it, you can read the contents label and otherwise confirm the gas you are switching to.

beanojones:

I just find 80's more comfortable in the water than 40's, though most 40's I have used have been Catalinas which makes a big difference apparently. Minor point: 80's always rack better than 40's as well.

Click to expand...

That's certainly because of the type of 40 you're using-- luxfer AL40's are MUCH easier to carry than 80s.

I put one on the left and one on right (out front like back mount) both AL80s but I use 80s for more of a logistical stand point on boats. Usually cant get 2 dives out of a 40 using the rule of thirds, where I can always get 2 dives out of an 80.

Thanks everyone for your input, some excellent advice and food for thoughts here.

FoxHound:

its going to be clipped off by the time you are switched to the 100%, and you are going to donate what you are breathing so that pretty well takes the long hose out of the equation.

Click to expand...

This is a very good point. Certainly makes things a lot easier if the 7ft hose is out of the equation. I think I'm going to need a fair bit of practicing and experimenting to get used to it before doing a real dive with it. So you suggest a 40" hose for the 100% as well? Not too sure if that's long enough for across the chest and around the neck? Will have to try it with my current 50% bottle on the right.

superspeed:

I put one on the left and one on right (out front like back mount) both AL80s but I use 80s for more of a logistical stand point on boats. Usually cant get 2 dives out of a 40 using the rule of thirds, where I can always get 2 dives out of an 80.

Click to expand...

Just out of interest, what sort of dives were you doing that require the 80cf 100% mix for 2 dives? I could probably do around a total of 36min of deco on a 40cf at 6m using a 20% reserve. I think the question is, how long would it take me to build enough experience to execute dives that's going to exceed that. I don't see it happening anytime soon for now... but then again...

Superspeed, what are your second stage hose lengths for the 2 stage / deco bottles?

I realize that this echoes what others have already said but I have been taught by two different Instructors lean mix on left / rich mix on right.
Gas switches ALWAYS GET VERIFIED!
Buddy or no buddy.

Hose lengths depend on the tank position and rigging.
I am starting to experiment with this very thing and a 40 inch will work but could be short for some divers.
I have used 80's / 72's and a 40 but not both together yet.
Still working with the stage rigging in SM.

It is fun to train but still getting the skills lined up before planning any serious ADV. dives or TriMix
One step at a time.

CamG Keep Diving....Keep Training....Keep Learning!