30# wing or 40# wing - still not clear...

[nereas]

Some divers dive with no ditchable weight, while others have a certain minimum of ditchable weight, and yet others have all their weight ditchable.

All divers have specific reasons for why they do what they do. All these reasons involve personal choices and result in trade-offs with pros-and-cons.

Those diving with no ditchable weight are normally wearing drysuits, and their argument is the suit is their back-up for a wing failure. Since they have no compression issues as with thick wetsuits, they can set their weighting to be neutral at the end of their dives, and use their wing or suit to establish neutral or positive buoyancy at the beginning of their dives when the air in their tank(s) is(are) heaviest. They are betting that they will never experience a double failure of both wing and suit.

Those diving with a certain minimum of ditchable weight normally want to be able to establish neutral buoyancy even at the beginning of their dives without relying on their wing or drysuit as an inflation device. These divers do not gamble unnecessarily. This is what I do, and therefore I am biased in favour of this method.

Those diving with all their weight ditchable are normally wearers of thick wetsuits, even double layered, and so they would need to ditch lots of weight if really deep to establish neutral buoyancy in an emergency (which then unfortunately turns into positive uncontrollable buoyancy on the way up). Or they may be beginners who want to be able to perform a buoyant emergency ascent, if needed, or else that is how they were taught, or else their B/C cannot accomodate any trim weighting of any kind, and they have not yet "graduated" to an integrated B/C or to a BPW. These are divers who "want a boost" up to the surface in the event they ever need to drop their weight belts. They are betting that the "boost" won't give them DCS, and hoping they will remember to exhale continuously rather than trigger DCI embolism on the way up.

Whether you need a 20 lbs wing, or 30 lbs wing, or 40 lbs wing, or 50 lbs tech wing, is a separate issue.

 

[cool_hardware52]

First, Thank you all so much!!

Do you always make some weight ditchable? By say taking off the weighted STS and adding two 4 pound ditchables? Or pretty much always you'll need more than 8lbs of added weight?

I know not enough info...
For this example say a 3mm shorty, al80 tank, no stuff, and a not buff 190lb diver?

TT

In warm water and thin suits you will quickly find that your rig is your ballast. Carry extra weight just to be able to ditch some is point less.

Rules of thumb that say XX% of your ballast should configured as ditchable simply don't work from the arctic circle to the tropics.

Now lets look at a 3mm shorty and al 80.

3mm suit will be about +4 lbs (maybe a little less)

an empty al 80 is + 4 lbs

That means you need about 8 lbs of total ballast. A medium SS plate and harness is about 6 and a reg is about 2. 6 + 2 = 8 Bingo.

How much wing? Well you rig is about -10 lbs with a full tank, and your 3mm suit can only loose about 4 lbs.

Still wonder if you need a 40 lbs wing?

Tobin

 

[Turtle Time]

I Bought a 30# Halcyon wing BP set up used, this evening! I am exited to keep learning. You have helped me understand this much better. Now to play with it in the pool.
Next to learn about reg's.

Thanks
TT

 

[medic001918]

Congrats on your purchase. The 30# wing from Halcyone is a nice rig. It's what I use for my singles rig. I think you'll find that the wing will serve you well. I actually dove it with a wetsuit and steel tank and ended up not needing any ditchable ballast, but I could also swim it up from depth without working too hard. I use a Halcyon 40# wing for my doubles rig, which also doesn't use any ditchable weight when diving freshwater, and I use about four pounds for ocean diving. I do most of my diving with a drysuit now so I always have redundancy if I really needed it. Good luck and enjoy your purchase.

Shane

 

[nereas]

I Bought a 30# Halcyon wing BP set up used, this evening! I am exited to keep learning. You have helped me understand this much better. Now to play with it in the pool.
Next to learn about reg's.

Thanks
TT

So now you can do the field testing, consisting of 3 things:

1) Your 100 ft dive

2) Your full inflation at the surface

3) Foating the gear by itself

Be sure to update the board on how this all works out.

 

[Biodiversity_guy]

I am a cold water /dry suit diver with a DSS 30 lb lift bc, with the integrated weights attached to the plate, and a weight belt.

The more I dive the more stuff I end up hanging off of me: 30cf pony, camera, dive lights, REEF slate, brass (not plastic) fasteners, etc...

The bc has always been just fine. Never a problem with lift.

My main concern about 30 being too small a lift would be if the dry suit sprung a large leak so that the buoyancy from the suit disappeared and instead turned into a drag. I would be able to drop the weight belt, but a 40 lb lift might give me more (mental) security.

 

[cool_hardware52]

I am a cold water /dry suit diver with a DSS 30 lb lift bc, with the integrated weights attached to the plate, and a weight belt.

The more I dive the more stuff I end up hanging off of me: 30cf pony, camera, dive lights, REEF slate, brass (not plastic) fasteners, etc...

The bc has always been just fine. Never a problem with lift.

My main concern about 30 being too small a lift would be if the dry suit sprung a large leak so that the buoyancy from the suit disappeared and instead turned into a drag. I would be able to drop the weight belt, but a 40 lb lift might give me more (mental) security.

If you are weighted so that you are eye level at the surface with no gas in your wing and a full cylinder, and your Drysuit is not more than 30 lbs positive you will have enough lift, even with a total failure of your Drysuit.

OTOH, if you have added gear and or ballast so that you are require your wing be substantially inflated to remain at the surface with a full cylinder you could be at risk in the event of a total drysuit failure.

If this is the case the solution is to cure the over weighting, not a larger wing.

Tobin