Question re: Wing Lift

[djensen]

I currently have a back-inflate BC with 25 lbs lift, and am looking at buying an 18 lbs plate & wing.

I dive drysuit with 36 lbs lead, but no pony bottles, twins or other heavy gear. Opinions vary wildly on this question so I'm looking for a consensus.

Is 18 lbs lift enough for cold water diving?

Thanks

 

[elan]

In theory its enough if you can establish positive buoyancy by ditching your weight in case you flood your drysuit. So most if not all your weight must be ditchable.

In practice I would not go for a wing with less than 30lb of lift

Another factor is if you dive rough seas it might not be comfortable though.

 

[djensen]

Yes. I could ditch 20 of 36 lbs. I see your point re: rough seas...

 

[CT Sean]

The standard answer is the wing has to do two things: compensate for the buoyancy change of suit compression (assuming less of an issue with a drysuit vs. a 7mm wetsuit) and gas use and float your rig without you in it - should you ever need to remove it for some reason. If that 16 lbs of non-ditchable weight is attached to the BC I would guess the BC is going to the bottom should you ever have to get out of it in the water.

There's a wing calculator link in the BC subforum, http://www.scubaboard.com/forums/bu...ems/158370-ultimate-wing-lift-calculator.html that helps determine lift requirements based on gear configuration

 

[red_barbarian]

If you ever experience a bubble in your dry suit feet the wing will not have enough lift to allow you to get your head back up. I would guess you need something in the mid-thirties for the weight your wearing.

 

[cool_hardware52]

I currently have a back-inflate BC with 25 lbs lift, and am looking at buying an 18 lbs plate & wing.

I dive drysuit with 36 lbs lead, but no pony bottles, twins or other heavy gear. Opinions vary wildly on this question so I'm looking for a consensus.

Is 18 lbs lift enough for cold water diving?

Thanks

First we know nothing about how buoyant you drysuit actually is. "36 lbs lead" says nothing about what you are using for a cylinder. Big difference between a buoyant al 80 and a PST 104.

Second we don't know how inherently buoyant your current BC is.

I've never wanted to be dependent on ditching ballast to solve a failed drysuit issue. It's just one more thing to do under stress. Some configurations don't allow it anyway.


I'd suggest testing your suit to determine how buoyant it is with minimum gas in. Then determine how negative your rig will be with a full cylinder. Which ever of these two numbers is larger will determine minimum required wing lift.

Divers require "buoyancy compensation" to compensate for the change or potential change in the buoyancy of their exposure suits. Colder water means more buoyant suits.

There's a reason why 17-18 lbs wings are popular in the tropics and 30-35-40 lbs wings are common in colder regions.................

Tobin

 

[g1138]

How negatively buoyant is your camera? Your bolt snaps and attachments?
Any accessories you forgot to mention? Ounces add up. You're going to be limited in your applications of an 18lbs wing for cold water diving.

Additionally it may provide a very narrow and possibly unstable platform if you have a very big profile in your cold water gear.

 

[PfcAJ]

The short answer is to buy a 30lb wing and call it a day. A tiny wing isn't gunna cut it.

 

[LowDrag]

The standard answer is the wing has to do two things: compensate for the buoyancy change of suit compression (assuming less of an issue with a drysuit vs. a 7mm wetsuit) and gas use and float your rig without you in it - should you ever need to remove it for some reason. If that 16 lbs of non-ditchable weight is attached to the BC I would guess the BC is going to the bottom should you ever have to get out of it in the water.

There's a wing calculator link in the BC subforum, http://www.scubaboard.com/forums/bu...ems/158370-ultimate-wing-lift-calculator.html that helps determine lift requirements based on gear configuration

Hey CT Sean, this is the second time I have seen this calculator. The only problem for me is that I can not get it to open. Any ideas? Thanks.

 

[djensen]

Ya. That link didn't work for me either. Thanks everybody for your input. Answers are as I expected. I covet the 18# wing for its very streamlined size, but it just doesn't look feasible/safe for the cold-water stuff. And, as CT Sean mentions, my non-ditch weight in the SS plate and back pockets very nearly equals the lift itself (!) That single fact alone pretty much makes the case. G1138 makes a good point too... I haven't added up all the small (seemingly insignificant) weights I hang off my body - snap bolts, lights, knives, camera(s), etc. Thirty lbs wing it is. Sometimes it just helps to talk it out