Where Did I Go Wrong?

[Mike Boswell]

After asking the experts and doing quite a bit of research, I purchased an Oxycheq 30#Wing and set it up directly on my DSS SS backplate (no STA). Using a full HP100 Steel tank and two weight pouches on the waist belt with 4 lbs of lead in each pocket, this rig should float* when fully inflated. It doesn't. It sinks - just barely - in sea water.

* Rig Buoyancy = Tank (-10) + Plate (-5) + Reg (-2) + Lead (-8) + Hog Harness (-2) = (-28 lbs.)

I have noticed that when the tank is mounted, it is restricting the full inflation of the wing.

Everyone says the rig must float with a full tank. What should I do?

 

[ianr33]

Get an Aluminum backplate? Use less weight? Ignore it and just go dive?

 

[TSandM]

Put the lead in a weight belt. It will solve your problem.

This is a great example of what Tobin often says . . . rated lift on a wing may not be what you actually get with a tank attached to it.

 

[timle]

The worthington X7-100 is -10 full
The faber HP 100 is -15 full
The sherwood HP 100 is -11.5 full

But in the end this is just too close to call. The wing gets constricted by the tiniest amount by the plate and the tank and poof there goes some lift.

 

[Peter_C]

I have an older Oxycheq Signature 30# wing on a Freedom Plate. With an extra 5 lbs of lead attached to the plate and an HP100 or HP130, plus a canister light, unless I hit the inflator until the OPV cuts loose my rig sinks.

Point being, are you filling the wing until it comes out of the over pressure valve? If not try it. What you describe should not be that negative.

I will agree with TSandM that you should probably be carrying much of the weight on a weight belt.

 

[Eric Sedletzky]

I have an older Oxycheq Signature 30# wing on a Freedom Plate. With an extra 5 lbs of lead attached to the plate and an HP100 or HP130, plus a canister light, unless I hit the inflator until the OPV cuts loose my rig sinks.

Point being, are you filling the wing until it comes out of the over pressure valve? If not try it. What you describe should not be that negative.

I will agree with TSandM that you should probably be carrying much of the weight on a weight belt.

Peter you have an older Oxy wing which is a little wider and bigger than the Mach V. I'm figuring he has a M5 because that's all you can get now. And also the freedom plate is cut away so that allows the wing to inflate more.

But yeah I agree, more weight needs to be put on a weight belt.

 

[fisheater]

Also, the part of the wing that happens to be above the water isn't doing you any good, buoyancy wise.

 

[Tortuga68]

^ Indeed

 

[DA Aquamaster]

Having been diving since the 80's when excess lift was not considered a sin, and having seen numerous tank/BC/reg/integrated weight combination sink out of sight in total definance of the theoretical lift they were supposed to offer, I tend to depart from the herd of "experts" and advise people to go a little bigger in terms of lift when selecting a wing.

In my own experience I noted that the original version of the rec wing would not give the full advertised lift when used with certain flatter profiled plates and 7.25" and 8" diameter tanks as the wing got constrained between the plate and the tanks. Not real comforting when you are way negative with back gas, a stage and a deco bottle that "theoretically" should be neutral in that configuration. I now have a 55 pound wing that is "theoretically" excessive for my needs, but it forks fine has enough lift and does not have nay of the excess toca/hard to dump, etc horrors the "experts" suggest will befall anyone silly enough to use a wing with too much lift.

At this point you have a few options:

1. As Lynn states, put the weight on a weight belt

2. Consider whether you really need your current amount of weight. If you can spare a couple pounds, you can reduce the lead or save about 4 pounds switching to an AL plate. In either case, the rig would probably float by itself in sea water.

3. Having a rig that gets you neutral at max depth with you in it is esential. Having a rig that floats on the surface is nice, but is only a requirement if for some reason you have to take it off in the water and cannot clip it to a line to the boat or to a lift bag.

 

[Mike Boswell]

The worthington X7-100 is -10 full
The faber HP 100 is -15 full
The sherwood HP 100 is -11.5 full

But in the end this is just too close to call. The wing gets constricted by the tiniest amount by the plate and the tank and poof there goes some lift.

I agree that the wing is constricted by the tank, but since that is the way the wing is supposed to be used, one would think this constriction is taken into account when rating the wing. Tobin at DSS says he takes it into account, but I don't know if Oxycheq takes it into account.

My tank is the XS Scuba HP100, and according to them it is -10 lbs full with the valve. (see XS Scuba Worthington Steel Cylinder Specifications)