Wing lift minimums for BP/W?

[blake7]

I have a BP/W question about what would be considered minimally acceptable wing lift to float my gear. My situation is the following:

BP + BP weight + Harness + Reg + Full HP100 = -27 lbs
Oxycheq Mach V 30 lbs wing = +30 lbs

I have tested, and a 3lbs weight will very slowly sink the gear in saltwater or be almost neutral buoyancy.

Is that sufficient lift? Should I have more than a 3lbs margin? If I add any more negatively buoyant gear to my setup, how low can the margin be?

Thanks for any thoughts/opinions, I really appreciate it!

 

[GrumpyOldGuy]

If you always dive with a wetsuit, the added buoyancy of the suit will provide an ample margin of safety. Diving dry and have a suit flood might be ugly.

 

[Mr Carcharodon]

You should plan for the worst case. If 33 pounds is what you need to float with an almost empty tank then that is what you need. Have enough weight to use all the gas in your tank, after all if you are lighter what is the point of of having that gas. Do not go a lot lighter. Try to hit it within a pound.

 

[halocline]

I have a BP/W question about what would be considered minimally acceptable wing lift to float my gear. My situation is the following:

BP + BP weight + Harness + Reg + Full HP100 = -27 lbs
Oxycheq Mach V 30 lbs wing = +30 lbs

Have you considered taking some of the ballast off your rig? 27lbs negative is substantial for a single tank set up. It sounds like you could put at least 10 lbs on a belt or weight harness.

Assuming you're properly weighted, in your exposure suit it sounds like you're about 20-22 lbs positive. (27lbs minus the weight of the gas) That's a lot of positive buoyancy to not have any weight on yourself rather than on the rig. Just a thought.

 

[blake7]

Have you considered taking some of the ballast off your rig? 27lbs negative is substantial for a single tank set up. It sounds like you could put at least 10 lbs on a belt or weight harness.

Assuming you're properly weighted, in your exposure suit it sounds like you're about 20-22 lbs positive. (27lbs minus the weight of the gas) That's a lot of positive buoyancy to not have any weight on yourself rather than on the rig. Just a thought.

I was mostly worried about floating the gear. I do have a BP weight that I could move to my belt, but I don't like wearing more than a 10 lbs weight belt.

I am actually ~25 lbs positive with the dry suit and wear a 6lbs weight belt to offset the empty gas. If the dry suit floods, I would have to drop the weight belt and swim up against the flood with a fully inflated wing. I have not tested, but I don't think that all of the 27 lbs positive would become negative on a flood.

Should I really have a wing that can float all the gear + full tanks + flooded dry suit? I would need a >40 lbs wing and that seems really excessive. I was going with the one failure model, either wing or dry suit and making up the difference by swimming up or using my SMB for emergency flotation.

 

[diver 85]

I'd put everything on & give it a test run---no dry labbing here......Sooner or later you'll have to anyway.........

 

[halocline]

I was mostly worried about floating the gear. I do have a BP weight that I could move to my belt, but I don't like wearing more than a 10 lbs weight belt.

Removing some weight (like your BP weight) from the rig would solve the problem of floating it with the 30 lb wing. It also gives you more weight to ditch in the case of a drysuit flood. You might try one of the weight harnesses; people seem to like those better than a weight belt. I dive in warm water so I don't use nearly as much weight.

 

[dkktsunami]

You should plan for the worst case. If 33 pounds is what you need to float with an almost empty tank then that is what you need. Have enough weight to use all the gas in your tank, after all if you are lighter what is the point of of having that gas. Do not go a lot lighter. Try to hit it within a pound.

One "worst case" scenario might be hitting the water with a full tank and not having the capacity to float if something went wrong. Minimum weight to remain at ten feet with a near empty tank, but enough potential lift to float with a full tank.

 

[Bob DBF]

When moving to a BP/W I ordered a 40# Oxycheq Mk5 because the jacket I had been using was 40# lift and it had served me well for years. A 30# was sent in error and I returned and replaced it with the 40# but I really did not see any significant size difference in the two. The way I look at it, If you don't need the extra 10# of lift you don't need to use it, but..........

By the way it is the best peice of dive gear I have purchaced since the SPG came into my price range decades ago. I use it on a Hammerhead BP or on a Freedom Plate depending.

Bob
-----------------------------------
I am not to be used as an example.

 

[Scared Silly]

To paraphrase Tobin - a wing has two purposes, to float you and your gear at the surface at the beginning of a dive and to compensate for the loss in buoyancy in your thermal protect while a depth.

Even with a fully flooded dry suit you will still have some positive buoyancy. As for the wing floating your gear without you in it. It sounds like it did that just fine with a bit of room to spare. My only concern would be if you added some addition gear to your rig like a can light. Can you take an equivalent amount off from your BP weight?