new bw&h with 60# lift is it to much

[jrc]

I Just Got A Halcyon Evolve 60 Wing, Ss Backplate & Harnes. Have Not Had A Chance To Use It. Will Be Diving With Dry Suite, Double 108's. Wondering If 60# Lift Is To Much. Any Help Would Be Greatly Appreciated.


John

 

[Packhorse]

My understanding of it is that the wing needs to float the weight of your gear and compensate for the loss of bouyance caused by pressure on your wetsuit. Since you dont have a wet suit then I guess you can disregard that part.
Now how much is the in water weight of your plate, doubles, manifold, regs, weights, light, reels etc ? Figure this out and then add a few lbs to get it positively bouyant, take into account that the wing may not offer its full 60lbs of lift when squashed between plate and tanks and away you go.
You could also dive it. See how bouyant your rig is, let 1/3 of the air out and if its still bouyant enough then you could assume that 40lb lift would be enough.
I found that my 44lb wing offered too little lift for my Asahi tanks. So I ended up swapping them for some 100cf HP fabers that saved my 9lbs.

Hope this helps, if it doesnt Im sure someone more knowledgeable than I will soon come along and let us both know.

 

[Packhorse]

Oh yeah I watched the Omen last night and recon this was the best horror movie I have seen since the original. There was also a dvd extra about revalations and the number 666 and how this number always pops up in things like bar codes and stuff and how in hebrew WWW can be linked to 666!!
Why am I telling you this? This is my 666 post on SB!! spooky aye!

 

[cool_hardware52]

I Just Got A Halcyon Evolve 60 Wing, Ss Backplate & Harnes. Have Not Had A Chance To Use It. Will Be Diving With Dry Suite, Double 108's. Wondering If 60# Lift Is To Much. Any Help Would Be Greatly Appreciated.


John

Hi John,

Your wing does have two jobs, float your gear at the surface without you in it, and compensate for the loss of buoyancy of your exposure suit. Additionally with doubles you need to consider the weight of the gas.

Your rig is unlikely to be more than ~ 30 lbs negative, full 108's + SS backplate + regs, can light, reel etc. Maybe 35lbs a the max.

How buoyant is your DS? If we put you in your undies, and suit and put you in the water how much lead would you need to get neutral? I'm going to guess and say 25lbs. This is just a guess, and you'd be far better off testing yourself, but fo rthe sake of this example I'll say 25 lbs. If you suffer a total flood of your suit how much of this buoyancy will you loose? We can agree no more than 25 lbs and likely a fair bit less, as total floods are hard to achieve. Lets say 20 lbs.

Your tanks will hold ~18 lbs of air or nitrox, and if you have a long shallow stop you may well want to be able to inflate your DS a bit, say 5 lbs of gas.

That means you need to start the dive negative by the weight of your back gas (~18 lbs) and the extra gas for your suit (5) That's 23 lbs negative. Now add the 20 lbs you can loose from flooding your suit. That totals 43 lbs.

If you jump in the drink with full tanks and an open DS zipper you need at least 43 lbs of lift to get back to the surface.

Will 43 lbs float your rig? 43 > 35 so you are OK here, even with a stage or two.

Is a 60 lbs wing too big? Well maybe, if my assumptions are correct about your DS (and they may well not be) 60 lbs is a bit more than you need. Something ~45-50 would be OK.

Is a 60 lbs wing going to ruin your day? Probably not, but it will be a little more drag and little harder to vent than a smaller wing.


Tobin

 

[jrc]

Thanks For All Your Help

 

[PvilleStang]

Man, a 60# wing on a set of 95's is sometimes pushing it, since I rarely ever have to deflate past halfway. Now take this into account: I rarely get to see any water with salt in it, so when I do, I dive my double 95's, Aluminum BP, OMS 60# wing, SS bands, OMS 200 bar manifold, and its sitting about neutral. Add in the difference between 95's and 108's in metal (an extra 3-4 inches maybe, pulling that one out of my arse since I'm not sitting in front of a set right now), and 2# for extra air (26 cu ft. of air at 2400psi, not accounting for the extra overfill) and I can see using a 100# bladder on there.

 

[rongoodman]

At least for Worthingtons, the LP95s and LP108s are both -8 lb apiece when full.

 

[JeffG]

Man, a 60# wing on a set of 95's is sometimes pushing it, since I rarely ever have to deflate past halfway. Now take this into account: I rarely get to see any water with salt in it, so when I do, I dive my double 95's, Aluminum BP, OMS 60# wing, SS bands, OMS 200 bar manifold, and its sitting about neutral. Add in the difference between 95's and 108's in metal (an extra 3-4 inches maybe, pulling that one out of my arse since I'm not sitting in front of a set right now), and 2# for extra air (26 cu ft. of air at 2400psi, not accounting for the extra overfill) and I can see using a 100# bladder on there.

LOL

I guess my using a 38lb wing with double 130's in fresh water is extreme then. 100lb wing. Yaaaa Baby.

 

[JeffG]

Add in the difference between 95's and 108's in metal (an extra 3-4 inches maybe, pulling that one out of my arse since I'm not sitting in front of a set right now)

There is a difference between weight on land and buoyancy.

 

[matt_unique]

As long as you can empty your wing, the lift capacity will not be "too much".

As Jeff points out, weight on land is not the same as weight in the water. Let's assume you weigh 170 and carry 100lbs of gear. You don't need 170 lbs of lift to be neutral.

--Matt