Sidemounting with more than 3 tanks

[Winstone]

Hello fellow Sidemounters , I’m looking to extend my bottom time and playing with the idea of adding an additional Alu 80 to my rig on technical dives. I was just wondering how that has worked for others. Configuration would be 3x Alu 80’s for bottom gas and 1 x Alu 40 for deco. Any feedback on how that worked out with trim, weighting rigging and how manageable it was. Thank you

 

[Dsix36]

I am VERY new to sidemount!! I did however do a dive with 2 AL80s as my sidemount tanks along with 2 AL80 stages and one AL40 for deco. Adding the stages in regular rigging was effortless and did not effect trim. I nose clipped the AL40 on my butt D-ring without issue but did find it difficult to get oriented properly to remove it, very difficult as a matter of fact, since it twisted during transport. I did not change any weighting but found myself very light at the end of the dive with all 4 of the AL80s getting tail light. I managed to hold my stops but at 3-4' it was a beotch to do so.

 

[mr_v]

2LP85s + AL72 + AL40 = no issues. AL72 and AL40 clipped to the bottom so that LP85s are no top. Granted, AL72 and AL40 were dropped off in cave where appropriate, but I did not have any issues with dropping or removing these tanks. Next time I will do five tanks by adding 2 AL72s and one AL40 to the LP85s. Will keep you posted. Generally, I don't like clipping AL40s to the butt D-ring.

 

[halocline]

Generally, I don't like clipping AL40s to the butt D-ring.

I find it very comfortable and convenient as long as the AL40 isn’t full and is light enough for the bottom to float. But, I rarely carry the deco tank far into a cave; it usually gets dropped either at the main tie-in or someplace close by. But I like hanging it on my butt on the deco stops, I’ve even done that with a AL80 of 50% O2 that’s getting too light to be comfortable staged normally.

 

[Bowers]

I dive with primary tanks rigged per usual, then my stages clipped underneath, one on each side (lean left, rich right). I clip primary tanks forward on my waist with sliding d rings, then stage bottles are clipped to the waist strap more toward my back on the same fixed d-rings that hold my butt pouch and with a few inches of bungee between tank band and bolt snap to allow it to reach between my body and primary tank. The top of the tank is attached from the neck to the shoulder d ring with as short of an attachment as possible. with the top and bottom as described it keeps things trim and snug so I don't get the "gong" effect with every kick lol. Any more than 4 tanks and additional tanks get put on a leash at my butt to be rotated in when needed. Trims out great and my xdeep wing has no issues with it.

 

[merc97]

@mr_v questions for you, how do you find the buoyancy characteristics of al 72 vs al 80? Also would you consider divine al72s instead of al 80s in a non cave dive ?

 

[mr_v]

@merc97, AL72s suit my needs slightly better than AL80.

Compared to AL80, AL72 are a bit thinner, slightly less buoyant when empty, and are very close to 10L which makes some gas calculations easy when using BAR. As I do not like having too many tanks, I stick with AL72s for dedicated CC bailout or OC stage tanks.

I would not dive these tanks in OC configuration because I need weight and I don't like how these may ride close to empty. However, it does not mean that you can't dive them. The best way to find out whether a tank is good for you is through experimentation.

 

[Winstone]

2LP85s + AL72 + AL40 = no issues. AL72 and AL40 clipped to the bottom so that LP85s are no top. Granted, AL72 and AL40 were dropped off in cave where appropriate, but I did not have any issues with dropping or removing these tanks. Next time I will do five tanks by adding 2 AL72s and one AL40 to the LP85s. Will keep you posted. Generally, I don't like clipping AL40s to the butt D-ring.

Thank you and let me know how it goes with 5 I am presuming you are using a scooter?

 

[J-Vo]

With practice, side tanks and 4 stage/deco tanks can be done proficiently. I dive 108s + 3 80s fairly regularly. The winder makes it a bit more difficult, but practice practice practice.

 

[LFMarm]

With a ChOptima the max I am comfortable with is 2xA80s in addition to the side tanks. When a 5th tank is needed, it gets clipped to my butt d-ring.