Wing Size/Doubles Weighting Math

[Rilelen]

I typically dive a 60lb wing with LP85s and HP100s…but I also sometimes dive LP104s or dive wet (Florida), and I like having that extra lift. I can say I haven’t had an issue managing the bigger wing with the 85s.

 

[crofrog]

I typically dive a 60lb wing with LP85s and HP100s…but I also sometimes dive LP104s or dive wet (Florida), and I like having that extra lift. I can say I haven’t had an issue managing the bigger wing with the 85s.

Have you dove a 40lb wing with them?

 

[Rilelen]

Have you dove a 40lb wing with them?

I have, but not often.

 

[JHumbert15]

Personally the thing I’d question more is the use of 2 AL40s (50% and 100%?) vs. an AL80 of 50% on a typical Great Lakes dive where LP85s are are your choice of tanks for backgas. Multiple gasses make sense on deep stuff, but OC you’re going to also be on bigger tanks at that point for back gas. To me getting out of the water a couple min quicker doesn’t outweigh the safety of more gas available deeper, having only a single gas switch with no opportunity to grab the wrong reg, and the economic saving of only needing to refill one deco bottle each dive. Outside of the very earliest part of the season thermal exposure on deco isn’t a huge issue as the thermocline is below the longer shallow stops.

Yeah, this is def a fair point. Thanks again!

 

[JHumbert15]

I typically dive a 60lb wing with LP85s and HP100s…but I also sometimes dive LP104s or dive wet (Florida), and I like having that extra lift. I can say I haven’t had an issue managing the bigger wing with the 85s.

Yeah in the future I'm looking into getting some PST LP104s because I've heard good things, and I may be moving to Florida next fall (unsure yet). If I do and I get those to start any cave training, I'd definitely get a 60, but I'm too concerned about having trapped gas in a 60lb wing with with 85s and it being uncomfortable to dump gas.

 

[Cio]

40# is fine.

 

[PEDiver]

I dive LP85s with a 45# wing and drysuit with no issues. Even with a stage + deco bottle the 45# wing is fine. I have a 60# wing I use with my HP133s/LP104s. The 60# wing feels a little big on the LP85s IMO.

 

[jeffmg]

The wing compensates for the weight swing of the gas in cylinders as you breathe them down

Doubles + single deco stage = 40lbs
Doubles + multiple stages = 60lbs

 

[crofrog]

The wing compensates for the weight swing of the gas in cylinders as you breathe them down

Doubles + single deco stage = 40lbs
Doubles + multiple stages = 60lbs

How negative is each stage when full

 

[jeffmg]

How negative is each stage when full

SCUBA Cylinder Specifications – Huron Scuba, Snorkel & Adventure Travel Inc. PADI 5 star IDC in Ann Arbor, MI

huronscuba.com

Full to empty is around a 6lb swing with air/nitrox
Deco 50% or 100% is a little less
A lot less when you start adding helium