Wings suitable for both double-7s and double-12s

[BarryNL]

What wings are considered "DIR" and would be suitable for use with both double-7 and double-12 litre tanks. Tanks are steel, and diving will be mostly cold water in a drysuit.

Also, the wing would need to provide sufficient lift for at least one and if possible two stage bottles - presumably 40cu.ft aluminiums.

I've looked at the Dive Rite classic - would this be too big for double-7s? Would it be OK with wider spaced double-7s?

 

[rjack321]

What wings are considered "DIR" and would be suitable for use with both double-7 and double-12 litre tanks. Tanks are steel, and diving will be mostly cold water in a drysuit.

Also, the wing would need to provide sufficient lift for at least one and if possible two stage bottles - presumably 40cu.ft aluminiums.

I've looked at the Dive Rite classic - would this be too big for double-7s? Would it be OK with wider spaced double-7s?

Double 7s? Those are pretty small why not just use a single 12-15L tank?

For the 12s, I use a 55lb Halcyon wing just fine. I also had a Dive-rite "Recwing" once and it worked fine too, although I didn't like the asymetrical routing ot the exhaust hose (its not in the center, but off to the left a little).

 

[BarryNL]

Double 7s? Those are pretty small why not just use a single 12-15L tank?

Three reasons:

- I don't want to keep swapping my hoses around on my first stages when I switch between a single tank and doubles.

- Pretty difficult to get the safety of an isolator manifold on a single tank.

- Balance - double-7s spread the weight out more evenly - a single 15 is pretty unstable.

 

[*Floater*]

I would use a 40# wing, I prefer donuts so I'd go with H Evolve 40 or one of the other similar wings now available from Oxycheq, Agir, DSS, ... - just make sure to note the difference in the shapes of the wings. The ones with wider rears place more lift down there which may or may not be something you like.

The 40 wing might be a little big for the 7's, and I don't think double 7's are typical in DIR circles so there's probably no recommended wing for that. A dedicated DIR diver would probably just buy a dedicated singles reg with the right hose lengths and use that instead. See here for something related: http://dir-diver.com/en/knowledge/single_hvalve_doubles.html

 

[jjones9527]

What wings are considered "DIR" and would be suitable for use with both double-7 and double-12 litre tanks.

The DIR answer would be a wing that provides sufficient lift to support the equipment you are carrying, but not so large as to possibly trap gas or cause excessive drag. In my experience a 40lb wing is great for double Al 80's and a stage or two. For my 130's I use a 55lb wing, which also provides enough lift to carry a few extra bottles. I'm not sure what 7L and 12L translates to in cubic feet, but theres a rough guideline. Of course the usual stuff applies as well (no dual bladders, no bungees, no shoulder pull dump, short corrugated hose, etc.)

 

[cool_hardware52]

What wings are considered "DIR" and would be suitable for use with both double-7 and double-12 litre tanks. Tanks are steel, and diving will be mostly cold water in a drysuit.

Also, the wing would need to provide sufficient lift for at least one and if possible two stage bottles - presumably 40cu.ft aluminiums.

I've looked at the Dive Rite classic - would this be too big for double-7s? Would it be OK with wider spaced double-7s?

Barry,

Take a good look at http://dir-diver.com/en/knowledge/how_much_lead.html

Read all the way down the page. Stages are not part of your weighting, and should not impact required wing lift.

You want one wing to use with two very different set of tanks right? If so you have to size the wing based on the largest volume, i.e. the 12's. Will that wing be optimum for your rather small 7's? I doubt it.

You need to start your dive negative by at least the weight of your back gas + 2 or 3 lbs. Double 7's will hold about 9 lbs of gas, and double 12's will hold about 16 lbs of gas.

You also need to be able to compensate for a total failure of your dry suit. If we put you in your undergarment and drysuit and put you in neck deep water and vent your all the gas possible from your suit how much lead is necessary to get you neutral? I'll assume 24 lbs., your numbers will likely vary. Whatever the minimum buoyancy of suit is, it represents the max you could loose in a total suit failure.

That means with with 7's you need 24 lbs + 9 + 3 = 36 lbs of lift at a minimum, with 12's you need 24 + 16 + 3 = 43 lbs.

If you start the dive with a functioning drysuit and full back gas (12's) , how much of your ~43 lbs lift wing will you need to stay at the surface? 14 +3 = 17 lbs. How negative is an al 40? Rigged and full a 40 is about -4 lbs. How much wing capacity remains to offset the negative buoyancy of an al 40? 43-17 = 26 lbs. 4 lbs out of 26 is trivial.

What happens if you have a total drysuit failure and need to use your wing to compensate for the lost buoyancy of the suit? If it's early in the dive you can drop the deco bottle, or hand it off. If it's late in the dive you will be at least 4 lbs lighter due to back gas consumption.

You also need to check that you have enough wing to float your rig at the surface without you in it. Just add up the numbers for negative buoyancy of your tanks, plate, regs, bands and manifold, can light etc.

Remember these are just examples, and you need to determine the buoyancy of your suit, and use the negative buoyancy figures for your own gear.

Tobin

 

[rjack321]

Three reasons:

- I don't want to keep swapping my hoses around on my first stages when I switch between a single tank and doubles.

- Pretty difficult to get the safety of an isolator manifold on a single tank.

- Balance - double-7s spread the weight out more evenly - a single 15 is pretty unstable.

Ok. Unfortuantely I can't help you mcuh though - these are much smaller than I've ever tried. I'd guess you'd want/need a set of bands with wide spacing to be able to use a standard iso manifold?

There's so little gas in these that I'd guess a 35-40lb wing would be about right. That what I use with AL80s in MX. Smaller is nice when you can get away with it. Double 12s for me are too heavy for a 40lb wing in cold water + drysuit in my home waters though. Some people down in Monterey use pretty small wings on 12L tanks or their US equal HP100s. I think they are underfloated but maybe not. At some point you just need to try some of the alternatives.

 

[limeyx]

Ok. Unfortuantely I can't help you mcuh though - these are much smaller than I've ever tried. I'd guess you'd want/need a set of bands with wide spacing to be able to use a standard iso manifold?

There's so little gas in these that I'd guess a 35-40lb wing would be about right. That what I use with AL80s in MX. Smaller is nice when you can get away with it. Double 12s for me are too heavy for a 40lb wing in cold water + drysuit in my home waters though. Some people down in Monterey use pretty small wings on 12L tanks or their US equal HP100s. I think they are underfloated but maybe not. At some point you just need to try some of the alternatives.

12's are HP-100's right? The Halcyon explorer 40 is a decent choice for them for my setup. (Drysuit, single AL40).

the 40 is pushing it a bit for an AL80 and an AL40. The 55 is a better choice in that case.

 

[Seadiver5]

Seatec Seahorse is my favorite wing at this time. They are somewhat difficult to find in some area's but well worth the effort

 

[BarryNL]

Barry,

Take a good look at http://dir-diver.com/en/knowledge/how_much_lead.html

Read all the way down the page. Stages are not part of your weighting, and should not impact required wing lift.

Erm, I understand that you certainly never use your stages as part of your weighting and need to be able to hold a 5m stop without them but they do impact required wing lift. You need sufficient lift to be able to float you at the surface with full doubles and with full stages, which is more lift than you need for the doubles alone.

In terms of lift I guess I need at least (assuming 220 bar in all tanks):

6.3kg (14 lbs) for the gas in the doubles.
3.7kg (8 lbs) for the gas in the stages.
2kg (4.5 lbs) for the stages themselves.
----
= 12kg (26 lbs) for the tanks+gas.

Plus whatever is needed on top of this to safely float my head out of the water on the surface. I guess around 45 lbs lift should be sufficient.

Actually, I believe DIR Zone make a 20kg (44 lbs) lift wing - anyone know if this would be suitable for the double-7s.