proper sized bc for doubles

[Biodiversity_Guy]

I am slowly moving into the tech realm. I have got a couple of steel 100s I am doubling up. I will be getting a new BP/W setup but I am not sure what sized wing to get (lbs of lift).

Is there an easy rule of thumb? Thoughts?

Thanks in advance.

[Kees]

Assuming they're HP100s you're looking for a doubles wing with approximately 40lbs of lift. A 40lb doubles wing will also work with most similarly sized tanks with a diameter of 7.25" like Al80s or HP102s. If you're very overweighted, 40lbs might not be enough. That's a weighting problem though, not a wing size issue.

If they're LP95s or other large 8" diameter tanks you're probably looking for something around 55-60lbs. One of my dive buddies uses a 40lb wing with double HP130s (about the same size as LP95s) without issue, so there's a little flexibility here.

Of course, this is assuming a well-designed wing designed for doubles with no bungees. Personally, I'm a big fan of the Halcyon Evolve donut style wing, but there are a number of manufacturers out there that make wings of various shapes, sizes and qualities. If you can, try a couple out and see what you like best. Some of the well-known names include; Deep Sea Supply (DSS), Dive Rite, Halcyon, Highly Optimized Gear (HOG), and Oxycheq.

If you come out to a Tweek, we have a bundle of Halcyon Evolves, a Halcyon Explorer (a horseshoe design) and maybe a few Dive Rite wings you could try, if you're interested.

[Grateful Diver]

Halcyon Evolve 40 or a Deep Sea Supply Torus 49 would work very well with those tanks ... I've used both. The Evolve 40 is adequate, but might not suit your preferences on surface swims. The Torus 49 is a bit less expensive, and will sit you a big higher out of the water on surface swims. Both are awesome wings with high scores in the quality and "grin factor" categories.

DSS Torus 49 on the left ... Halcyon Evolve 40 on the right ...



... Bob (Grateful Diver)

[BDub]

I have a 38lb wing I use with hp100's and a deco bottle and it's ample lift for that setup.

Anything more than that (8" tanks and/or multiple stage/deco bottles) I use a 55lb wing.

[Diver_C]

I use an Evolve 40 for my HP100 doubles, and like it a lot. Good luck with your decision!

[Biodiversity_Guy]

Excellent. Thank you. Most helpful.

I dive a DSS now, and have enjoyed it for 300+ dives.

I will be looking at other brands before I make my final decision on the new setup.

[CaptnJack]

I use 55lbs for al80s, steel 85s and 100s here in Puget Sound but it really is a bit large. It works but I notice it. 40-49lbs would be ideal but ends up being a bit on the small side for most people in 8" diameter tanks like 95s.

[dsteding]

People may say 40 pounds is adequate, but make sure it can float your rig with full tanks if you boat dive . . .

I bet 50% of the BP/W rigs people use around here (especially single tank rigs) won't because of the use of large steel singles, can lights and lead weight on cam bands and such.

But, what do I know, I'm a cyberdiver.

[LCF]

Well, I use a 40 lb wing with double LP 85s or double HP 100s, and I KNOW it will easily keep the tanks at the surface, because we doff gear in the water to get back on our boat It's fine with one deco bottle, but beyond that, i'd want more lift at the surface, because I like to be able to get my whole head out of the water.

One thing to look at is wing shape. Depending on how you balance with your tanks, you may want a wing where you can park gas in the upper arc, or one where you can park gas in the rear portion of the side pontoons. The cut of the wing can affect how easy it is to put the gas in the wing where you want it. (I like a wing with a big upper arc and broad shoulders, because I'm head-heavy in anything doubled.)

[kagey747]

Back to what Kees said... go and try out several different wings so you know how they float/trim YOU out with YOUR gear and body composition. What works for one person might suck for another.

[dsteding]

Well, I use a 40 lb wing with double LP 85s or double HP 100s, and I KNOW it will easily keep the tanks at the surface, because we doff gear in the water to get back on our boat It's fine with one deco bottle, but beyond that, i'd want more lift at the surface, because I like to be able to get my whole head out of the water.

Full tanks, Lynne, full tanks. Although I suppose you still have full tanks even after a dive . . . and, don't you use an aluminum plate and lots of weight on a belt?

Point is this:

Two full HP 100s are ~22 pounds or so, add bands (2), plate (2), regulators, (6), and a can light and you're getting close to 40 pounds. The point you make about wings not delivering all the lift they are rated for means you can be really close. Add a small v-weight and you may be over . . .

I'm not saying 40 pounds isn't sufficient, I'm just saying verify that it floats your full rig. I've had a few people doff their full rigs for one reason or another when diving off my boat and have them be very surprised to find out their rig doesn't really float, even with the OPV popping on their wing. Having ~$3000 or more in gear hang off of a gear line can be a bit disconcerting.

[Joshua Smith]

The flip side of having enough buoyancy is having enough weight. Make sure and breathe your new dubs down to <500 psi at least once and do a weight check. I saw a guy cork from 40' with 20 minutes of deco showing on his computer. He'd simply never had his doubles down that low before, and didn't know how positive he'd be. (He was fine, except for his pride.)

[CaptnJack]

I'm not saying 40 pounds isn't sufficient, I'm just saying verify that it floats your full rig. I've had a few people doff their full rigs for one reason or another when diving off my boat and have them be very surprised to find out their rig doesn't really float, even with the OPV popping on their wing. Having ~$3000 or more in gear hang off of a gear line can be a bit disconcerting.

I've seen the same. And I've and to get back into the boat with full tanks various times - it happens. You need a big enough wing to float the tanks and all accutrements. That's not an accu though

40lbs should be fine for 100s, but with air/nitrox, possibly a larger V-weight, SS plate and a bigger can light it starts getting iffy.

[Biodiversity_Guy]

Just wanted to say THANK YOU ALL for your helpful input. I can see having additional lift makes a lot of sense as more equipment gets attached to the BC--lights, bottles, camera, etc...

[LCF]

BTW, the wing I use is a Deep Outdoors wing, and I did see that Tacoma Scuba had a couple of them. The company no longer exists; the wings at TS are still at retail price, but they might be willing to cut somebody a deal if someone wanted them, as they are now "orphans".

Yes, Doug, I do use an Al plate, but now with a 6 lb V-weight. The rest of the 12 lbs I need with my doubles is on a belt.