Advice on wing for twins

[rjack321]

Yeah, I'm diving with AL80s and it's an issue I'm concerned about. So what's your suggestion?

I wouldn't worry about it. Trim for any set of doubles is almost always most problematic when you have little gas remaining and no gas in the wing. You will probably need a AL plate to avoid tipping head down, but whichever wing you end up with won't help much at this time anyway.

When you have fuller tanks you'll have compensating gas in the wing. Its position will have a small influence on trim but its with near empty tanks that the worst problems generally manifest themselves.

Any chance you could try a buddies plate/wing and just see how you settle in the water?

 

[MXGratefulDiver]

it'll fit the 95's better. its really the diameter which matters and the 60# fits the 8" tanks better. i can't find anyone (although i'm certain i'll find someone now) who likes the 95s, though, and 104s don't weigh noticeably more than the 95s...

ymmv, but i'd be shopping for 104s...

I know lots of people who dive in ... and like ... the 95's. You just won't find them hanging out at a certain West Seattle dive shop.

FWIW - I've got two sets of 119's ... which are basically high pressure 95's. Seein's how I got a second set, I guess you could say I like 'em.

But you're right, the Evolve 60 is waaaayyy wider than the Evolve 40 ... and far more suitable for 8" diameter cylinders.

Here's some pictures I took before I sold my Evolve 40.

The first shot shows a side-by-side of the Evolve 60 and the Torus 49 ... the second shows the Torus 49 and the Evolve 40.

 

[lamont]

I know lots of people who dive in ... and like ... the 95's. You just won't find them hanging out at a certain West Seattle dive shop.

FWIW - I've got two sets of 119's ... which are basically high pressure 95's. Seein's how I got a second set, I guess you could say I like 'em.

hmmm... you were actually down on my scorecard as "not liking..."

i did have double-119s for quite awhile but busted them up into single tanks and made my single-130s doubles... the 119s were heavier (and head-heavier) and never felt as stable to me...

ymmv....

 

[alan_lee]

Any chance you could try a buddies plate/wing and just see how you settle in the water?

Yeah, am using an alu plate. Will be taking the twins workshop that the local GUE shop will be conducting next month, so it'd be a good chance to get a feel of things.

 

[MXGratefulDiver]

hmmm... you were actually down on my scorecard as "not liking..."

i did have double-119s for quite awhile but busted them up into single tanks and made my single-130s doubles... the 119s were heavier (and head-heavier) and never felt as stable to me...

ymmv....

Initially I didn't like them ... then I learned how to dive them ... now I do. Personally I prefer how the HP100's trim out (plus they're lightweight) ... but they're just not enough gas for some of the dives I want to do. And switching back and forth between different sets of tanks felt awkward. So I settled on the 119's and got a second set. Now that I'm used to them, they feel nicely stable.

TBH - I think a lot of what one likes or doesn't like boils down to what you get used to using ... applicable to both wings and cylinders ...

... Bob (Grateful Diver)

 

[rjack321]

Yeah, am using an alu plate. Will be taking the twins workshop that the local GUE shop will be conducting next month, so it'd be a good chance to get a feel of things.

With such a thin suit you'll probably only need a couple of pounds of lead. So you'll mostly be relying on the arch in your back to trim the tanks out (way more than a high or low biased wing). I have used double AL80s mostly in shallow freshwater with a 7mm wetsuit, Al plate and 5lbs of lead. They are fairly easy tanks to dive.

Ps I dive with several women who are GUE full cave and they dive LP95s in Puget Sound just fine. Back when they were taking classes, HP tanks were rare and had funky angled genesis valves, so they learned to dive the 95s cause 108s were overkill for their girly SAC rates. Both are much taller than 5'8". Half the battle with tank trim is skill, they have plenty.

Hp119s were bigger and heavier than I needed so I broke mine up. They dove fine I just didn't need to beat myself up carrying that much gas.

 

[limeyx]

Yeah, am using an alu plate. Will be taking the twins workshop that the local GUE shop will be conducting next month, so it'd be a good chance to get a feel of things.

The workshop is with Gideon ? If so, I'd give him a call and get his advice -- he may even have a bunch of different wings you can try on for size so you dont have to guess about which one will be good for you.

 

[alan_lee]

Was walking to some of the local chaps who dive on twins, and they actually told me that diving on doubles actually makes me more negative even when I'm low on gas. Now, my very simply mind reckoned that if I'm currently neutral when I'm low on gas with a single tank, doubles would mean that I'll be double the buoyancy of a single tank. So that would mean that I'd have to double the amount of weight to keep me neutral? How heavy does the manifold, tank bands and a can light (on average) weight respectively? I'm diving in tropical waters with AL80s.

Cheers!

 

[cool_hardware52]

Was walking to some of the local chaps who dive on twins, and they actually told me that diving on doubles actually makes me more negative even when I'm low on gas. Now, my very simply mind reckoned that if I'm currently neutral when I'm low on gas with a single tank, doubles would mean that I'll be double the buoyancy of a single tank. So that would mean that I'd have to double the amount of weight to keep me neutral? How heavy does the manifold, tank bands and a can light (on average) weight respectively? I'm diving in tropical waters with AL80s.

Cheers!

You should be weighted so you are just slightly negative with near empty tanks, and empty wing, and minimum gas in your dry suit. That will allow you to add a little gas to your suit if you have an extended shallow stop.

There is no need to be a great deal more negative than you would be in a single.

I use the following numbers to estimate the required wing size:

Center section of manifold + tanks bands and bolts 5 lbs.

Dual regs, 5 lbs.

Modern can light 2 lbs.

SS Back plate and Harness 6 lbs.

These value are all a bit on the high side. I use them to estimate the size of the wing required.

I suggest you start by determining how buoyant your suit is with minimum gas in it. Once you know this figure every thing else is just arithmetic.

Tobin

 

[xiSkiGuy]

Now, my very simply mind reckoned that if I'm currently neutral when I'm low on gas with a single tank, doubles would mean that I'll be double the buoyancy of a single tank. So that would mean that I'd have to double the amount of weight to keep me neutral? How heavy does the manifold, tank bands and a can light (on average) weight respectively? I'm diving in tropical waters with AL80s.

Try the Stephen Ash party trick. Read posts #74-78