Bouyancy of Gear - why don't manufacturers publish it?

Quick thought - we all talk (often endlessly) about our bouyancy and trim, and I know that every new diver should be taught how to do a correct bouyancy check to test their configuration as we are all different in size, shape, and gear configuration. But - whilst the overall bouyancy might change, the bouyancy of a bit of kit in most cases will not.

Yes tank bouyancy will change as air is used, and neoprene will compress with depth and so on, but basically your dive torch, canister light, regulators and dive suit will have a initial bouyancy at the surface which has got to be addressed in order for you to correctly weight.

I have occasionally seen some items like dive lights give a weight and 'bouyancy' in their descriptions, and BCD's and wings will usually quote the maximum lift achievable (although I have only ever once seen a gear spec which specified whether the lift was in fresh or salt water). But why isn't this common for all spec's.

The spec sheet for a wetsuit in a specific size could tell you its dry weight - important for packing if you travel by air, and its relative bouyancy in fresh water, important for correct weighting.

I think this would make it so much easier to change weights from dive to dive if you needed to.

For example I have a neoprene 5mm two peice wetsuit (long suit plus a shorty that can go over it) - if I do an fairly active dive in the morning and just wear the long suit I need to set my weight accordingly. If in the afternoon I do a slow shallower dive and take my photography gear, so I put the shorty over the top for warmth as I'm not going to be very active, how much weight do I need to add for the extra layer of wetsuit and subtract for the camera gear?

I could do a weight check but it would be so much easier if I knew the bouyancy of each component and could just do it automatically.

I suppose I could do a check of all my kit and work it out, but it would be so much easier if for scuba gear this was in the spec.

Any thoughts or should we start to ask manufacturers this?

P

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Neoprene crushes over time and the buoyancy characteristics change, but not all that much. Wetsuits are manufactured in various sizes and thicknesses. Manufactures may make sizes XS, XSS, XSL, S, SS, SL, M, MS, ML, L ..... That's a dozen different sizes for each thickness - 3/2, 5/4, 7/6 maybe some variations. So we are dealing with 36+/- sizes and thicknesses AND to make it more interesting different manufactures may bid to make a product, so china 1 may make something this year and china 2 may make it next year.

Bottom line the buoyancy characteristics are something every diver is going to need to deal with as NO manufacture provides buoyancy characteristics on everything. You may know the weighting on some items but never all. I have been diving a long time and can count my weight checks I have done on my hands, less than 10. I tend to be a couple lbs heavy, but suck it up, and spend 5 minutes doing a weight check!

Remember to add 5lbs of weight if your tank is not empty assuming you're diving an AL80.