why am I butt-heavy?

[skip]

OK, so my fourth incarnation of a sidemount harness seemed to work just work, but then this last time, whenever I stopped to just hover, I'd float head up. This has been a consistent problem for me with all kinds of sidemount bc's/harnesses. More air in dry suit and work it to the feet, only makes me too positive overall. I have the wing about as low as it can go and have mounted weights (3lbs/6lbs) on each shoulder, and still when I stop, my head floats up and I go vertical. the tanks have been brought up just past my armpits and there is no way I can bring them up higher without having the entire tank width in my pits. They are faber 98's. I'm a short guy, 5'7". As long as I keep moving everything is fine, fins up, good trim, head down, but I can not hover motionless without going vertical. any suggestions?

-skip

[RN]

I have the same problem when I dive wet. I tried putting shoulder weights on but it didn't really fix the problem. I'm fine in a dry suit by adding air and working it to the feet. Fortunately that doesn't make me too light. The only thing I can think is too add weight somewhere to your rig so that when you add weight you're not too light. Maybe someone else will have a better suggestion. I'd be interested in fixing this problem in a wet suit.

[WJH]

Perhaps too much air in the head? ;)

WJH

[Mike Edmonston]

OK, so my fourth incarnation of a sidemount harness seemed to work just work, but then this last time, whenever I stopped to just hover, I'd float head up. This has been a consistent problem for me with all kinds of sidemount bc's/harnesses. More air in dry suit and work it to the feet, only makes me too positive overall. I have the wing about as low as it can go and have mounted weights (3lbs/6lbs) on each shoulder, and still when I stop, my head floats up and I go vertical. the tanks have been brought up just past my armpits and there is no way I can bring them up higher without having the entire tank width in my pits. They are faber 98's. I'm a short guy, 5'7". As long as I keep moving everything is fine, fins up, good trim, head down, but I can not hover motionless without going vertical. any suggestions?

-skip

Try moving your tanks up, that usually does it for me. It generally doesn't matter if I'm diving wet or dry.

Safe Diving

[cavediver256]

Just curious, have you tried a different tank size????

[DeWayne]

Perhaps too much air in the head? ;)

WJH

HeHe, I was thinking someone would do it, but I really expected a different part of the anatomy to be targeted in a less friendly manner, lol.

What fins are you wearing skip? I was a little bit foot heavy with the Nomad until I switched from Jets to a lighter fin (using DR's now.) If you have shifted your cylinders up as far as you can, have you tried shifting the air cell down some? I t took a bit of work on my home made rig to get the cell adjusted right. All I had to do with the Nomad was change my fins. Hope you get it dialed in.

[Webmaster]

OK, so my fourth incarnation of a sidemount harness seemed to work just work, but then this last time, whenever I stopped to just hover, I'd float head up. This has been a consistent problem for me with all kinds of sidemount bc's/harnesses. More air in dry suit and work it to the feet, only makes me too positive overall. I have the wing about as low as it can go and have mounted weights (3lbs/6lbs) on each shoulder, and still when I stop, my head floats up and I go vertical. the tanks have been brought up just past my armpits and there is no way I can bring them up higher without having the entire tank width in my pits. They are faber 98's. I'm a short guy, 5'7". As long as I keep moving everything is fine, fins up, good trim, head down, but I can not hover motionless without going vertical. any suggestions?

-skip


Yeah, I had the same issue and went to a less dense fin. That's why I have those OMS Slipstreams now.

Let me know if you want to run out to the quarry and you can try the Slipstreams and the intact pair of DR's I have left if you like.

Marbry

[Kelly Jessop]

Just curious, have you tried a different tank size????


I would agree. 95/98s can be a bad choice initially,try some 85s.

[Brian Kakuk]

You can try a few of things Skip,
1. As suggested already, switch cylinders to LP 85's or HP 100's

2. Tighten the gussetting bungee at the top of the air cell. This will force more air to the bottom of the air cell and give more lift where it is needed. This is the reason the bungee was added in the first place.

3. Again, as already suggested, Switch to a lighter fin. Dive Rite spring heel fins or Mares Power Plana Avante are great light fins for cave diving.

4. It sounds like you have moved the cylinders pretty high, but if you have not already done so, try sliding the cam band down on the tank to within 1 to 2 inches from the bottom of the cylinder. This should put the shoulder of the tank in your armpit. This is where I keep mine (much to the shegrin of Brett Hemphill) and though it allows the tank to hang a little bit lower, it keeps the valves forward, which is where most of the weight of the cylinder is. We are about the same hight, so hopefully this will help. Some divers like the tanks futher back, where the cylinder will lay much more horizontal and higher (the reason for using side mounts in the first place). This also puts the valve/first stage behind the divers arm where it cannot be as easily reached or seen in a free flow. I prefer the tanks further forward where I can get at the valves easier and use the weight of the valve for trim. BUT this allows the tank to hang a little bit lower....to each his/her own.

5. When I am swimming, I allow the cylinder to slide back just a little (valve under the armpit). As long as I am swimming, the trim is fine. When I have to stop and hover for a long period of time, I pull the tanks forward a bit by the valves and the trim changes immediately forward.

6. Throw a drysuit ankle weight around the neck of each tank. Make sure they do not obstruct the valve handle in case you need to do shut downs/feather the valve in a freeflow situation. You want to avoid adding weights if at all possible, try all of the other options first.

All of these techniques can be used with either the Nomad or the Armadillo.

Safe diving,
Brian

[tflaris]

i had the same problem using the ScubaPro Jet fins. Switched to Duve Rite Fins no problem.

[skip]

Just curious, have you tried a different tank size????

no, i've used the same tanks, faber 98's, LP....you know, those old white tanks with scubapro written all over them.

They are similar to PST 119's, so I have not tried the 119's. I also have 130's, but they are longer and my thought was that they would make the problem worse, not better.

I have the tanks about as far up my pits as I can stand. I can move them up a tad more and will try that. A buddy once used two ankle weights, snapped together to create a neck-weight! I haven't tried that yet either!

I can also move the wing down, maybe. It's pretty far down, like the pictures shown in Jason's thread on sidemount, including the strap that holds the ends down around the hips. However, I put the wing on the outside of the harness, not on the inside like Jason did....

I was wondering if on the inside of the harness it may force the air lower in the wing and not let it collect up higher? I put it outside because I was worried about getting enough lift with stages too. Guess I'll move it to the inside and see if that helps.

-skip

[skip]

Perhaps too much air in the head? ;)

WJH

I have been accused of having a big head, but not an air head! well, until now that is! maybe that ankle weight turned neck weight would fix that!

-skip

[skip]

Thanks everyone. plenty of suggestions and things to try. Marbry, I'll be back in town next week and maybe we can dive the local quarry and try out the fins, thanks for the offer. I can get some 100's too (from barry), and maybe some 85's...


-skip

[cavediver256]

Skip I am guessing here, but what are you using for your harness/lift??? Sounds like a homemade SM rig. I am not really sure what kinds of adjustments you may have with that, but on the Armadillo and Nomad, you have gusset control (bungies) on the upper portion of the wing to help force the lift to the bottom of the wing creating more lift right where you need it.

I don't know if moving the tanks farther up will be accomplishing much. Even if it did improve your trim, sounds like it would be too uncomfortable to wear. There has been lots of great suggestions, I am sorta curious as to what you will find that corrects you "butt heaviness".:roll:

[DeWayne]

Sounds like the wing on the outside of the harness could well be a contributing cause, allowing more air up top. I have a couple of sets of 85's you can give a try, if you don't mind driving 5 hours to get them (plus the return trip of course.) The old OMS Faber 85's are the best I have ever tried.

[Webmaster]

Thanks everyone. plenty of suggestions and things to try. Marbry, I'll be back in town next week and maybe we can dive the local quarry and try out the fins, thanks for the offer. I can get some 100's too (from barry), and maybe some 85's...


-skip

I have LP 104's, LP 85's and others if you want to try them. We'll get you sorted out.

Marbry

[rchrds]

Hey skip- sorry I'm not around- between marbry and I we could get you figured out- what may not be immediately obvious in my pics is that there is a 4lb weight immediately between my shoulder blades on the inside of my rig (where it doesnt catch on stuff.) This helps keep my longitudinal rotation in check. I dont like to rely on air in the feet to keep my head down- that is asking for trouble on downslope passages- easy to lose control, or have to fight to regain control at the bottom. Your bouyancy should work the same regardless of suit, dry/wet or fin type. If your rotation is that sensitive, your axis of lift and weight are too far apart. I assume you are using a transpac? If so, notice that not only do I have my wing as low as it will go (the tips extend below the waist belt) but that the entire rig is rotated so that the waist strap is actually quite low over my hips. The top of my wing is actually in the middle of my back- nowhere near my shoulders. It looks and feels strange at first, but works very well- but not with a nomad wing. (I just purchased one, cause my old wing completely ripped apart, and I'm already not liking it.) More to follow on the nomad wing. Anyway, the wing inside or outside should not make a difference- I do that to keep the wing completely under control, so it doesnt fly up just behind the shoulders and catch on stuff, which is very common in most people's sidemount rigs. A good indicator of how much my rig is rotated is that the chest strap should fall just above your drysuit inflator. Now- with the tank attachment point being on the waist belt (as opposed to the nomad where it is much lower) your wing, as described above, will have its center of lift directly below the waist belt.
So- a lot of stuff, it works for everyone I've ever set up like that, but many seem to like the nomad/armadilla (they are really the same thing.)

Jason