perils with no dive weight?

[Searcaigh]

membrane = membrane drysuit which is a thin material with no inherent buoyancy characteristics - e.g. think of a plastic bag.
Crushed neoprene drysuits have inherent buoyancy which is the same at any depth. In comparison to a neoprene drysuit whose buoyancy characteristics, and thermal characteristics change (reduce) with depth (as the neoprene is crushed by the water pressure as you get deeper).

@Gareth J FYI the OP does not wear a drysuit.

 

[hedonist222]

The question is if you can maintain your head comfortably above the water in a worst case scenario. Being able to swim in a pool when slightly negatively buoyant is one thing, but if you have surface waves, a big tank on your back, and seasickness to contend with, it's not that easy.

To create ditchable weight, you would need to add some buoyancy as well. I would use some closed cell marine foam, such as part of a life vest or a buoy. Then you can put weight into a harness, belt, or ditchable pockets in your BCD. That's similar to what Angelo's partner is doing.

Maintain my head above water with an empty wing?
Not very comfortably. I need a bit of air in the BCD.

So what you're saying is to add negative buoyancy in the form of weights, then counter that with artificial positive buoyancy (marine foam).

When would this be useful? In the event I needed more positive buoyancy? I'd then ditch the weights & benefit from the buoyancy of the foam?

Would I need this only on the surface or some scenario during the dive?
Is this assuming I've ruptured my bladder and cannot orally inflate?

Thank you.

 

[hedonist222]

(to another poster)

No, you are absolutely right.

A balanced rig may or may not include ditchable weight. The only time you *need ditchable weight or (redundant buoyancy) is when you are (purposely) diving unbalanced. That may include equipment you can ditch in an emergency, like a can light, scooter, camera equipment, etc.

The issue is likely because your XDeep AL bp weighs 6 lbs. Compare that with the Halcyon AL bp that is 2 lbs or the Steel bp that weighs 6 lbs or perhaps others.

That few lbs that you're overweighted isn't too bad. It should be quite manageable. If you can swim it up from depth without air in your wing when you're in your warm water wear, you should be fine.

You're also right that you don't add buoyant things to yourself in order to require more weight.

Do you have much gas in the wing at your last stop or at 10 feet? Ideally, you want the wing to be empty at 10 feet and still be able to hold the stop and make a controlled ascent.

If you're correctly weighted, the worst you will be at the surface at the beginning of the dive, is neutral. At the end of a dive with a mostly depleted tank, you would be a little positively buoyant, even if your wing didn't hold air. That's exactly what we want.

With some of the advice on having ditchable weight at all cost, you would think that those of us who dive a balanced rig are plummeting uncontrollably to the bottom when we jump in at the start of a dive. Um, nope.

Hope that helps...

I'm assuming you've addressed this to me.

At about 100/130 bar, I completely empty the bladder and continue the dive without air, ascent without air in bladder, and maintain a hover at 6 meters without air. I've tried this with 7 bar left in the tank and could maintain neutral buoyancy at the safety stop.

 

[happy-diver]

You have certainly lured out from the woodwork some funny ideas people today hedonist222

It is not you it is them, and getting where you couldn't invent such BS, but they do continually

Just tell them all that you promise to carry your easily deployable dsmb for surface buoyancy

 

[Ayisha]

I'm assuming you've addressed this to me.

At about 100/130 bar, I completely empty the bladder and continue the dive without air, ascent without air in bladder, and maintain a hover at 6 meters without air. I've tried this with 7 bar left in the tank and could maintain neutral buoyancy at the safety stop.

Yes, so you're correctly weighted.

I was asking about with your warm water wear, though. So no wetsuit, lighter or no booties, whatever you wear.

If you haven't tried it yet and suspect you will be just a few lbs over, it's very manageable.

 

[UCFKnightDiver]

(to another poster)

If you're correctly weighted, the worst you will be at the surface at the beginning of the dive, is neutral. At the end of a dive with a mostly depleted tank, you would be a little positively buoyant, even if your wing didn't hold air. That's exactly what we want.

I never want to be positive at the end of the dive. If you're positive you're not properly weighted, you can't hold a safety stop or deco stop, and that's dangerous.

Not a fan of the obsession some get (not accusing you necessarily) within the dive industry of using as little weight as possible, which sometimes turns into a dangerous situation of being underweighted. I would always want to be a one pound or two overweight than one pound or two underweight.

 

[grf88]

Regarding disconnecting and reconnecting the inflator hose a hose hat makes both easier. There are also adapters that don't need the collar pulled back to connect which make reconnecting much easier, this is especially true for dry suit hoses that are difficult to reconnect due to their location. There are also slide valves that can be installed in line. As for weighting I am of the camp that it is far better to have a couple of extra pounds or so. I also always have some form of redundant buoyancy whether it is my dry suit a DSMB or a lift-bag.
EZ-ON Adapter: Turns LP Reg Hose into BC/Drysuit Inflator Hose
BC & Drysuit Hose Quick Release Slider , Piranha Dive Shop |
On/Off Bc Shut Off

 

[hedonist222]

I would always want to be a one pound or two overweight than one pound or two underweight.

Why?
Why not balanced.

 

[UCFKnightDiver]

Why?
Why not balanced.

A balanced rig is when you are neutral or slightly negative at the end of the dive and can reasonably swim your rig up. If you're too negative then it means having redundant buoyancy (drysuit, dual chamber wing, perhaps a lift bag, etc.). A balanced rig does not mean being positively buoyant.

 

[Lorenzoid]

Why?
Why not balanced.

I interpreted @UCFKnightDiver 's statement that you quoted as meaning that while achieving a perfectly balanced rig is the goal, it is better to err on the side of being a tiny bit overweighted than a tiny bit underweighted. In a perfect world, a balanced rig is ideal. But things happen. For example, if you're working too hard and not fully exhaling, you can get a little too buoyant for comfort at the end of your dive when the tank is near-empty. Sure, that's when you're supposed to be doing the safety stop and staying still, but things happen. Maybe a whale shark passes by and you are gasping in awe as you furiously snap photos, not minding your breathing as perfectly as you should be. Also, if you weight yourself as you normally do for perfect balance but forget some item of gear you normally carry, like a light or a knife, you may end up a little too buoyant for comfort at the end of your dive. A pound or two overweight is not bad if you have to err on one side or the other.