What percent of weight should be ditchable?

[Kryssa]

I'm considering purchasing a Dive Rite Transpac and if I go with the ditchable weight pockets, I have the choice of 16 lbs total or 32 lbs total. When I dive dry, I wear 36 lbs. Obviously in warm water, it will be less but I haven't been out of the cold water or a dry suit since my DSD so I'm not sure how much less it would be.

So my question is... what percent of weight should be ditchable? If i were to dump 32 lb in an emergency I'd rocket to the surface for sure. So maybe I should get the 16 lbs ditchable and add the extra 20 lbs elsewhere? Or get the 36 lb pockets and do 26 lbs in the pockets and 10 lbs on the tank bands? I'm also expecting that I will lose some of that weight as I am new diver and still working on my trim.

So what do you think? 16 lbs or 32 lbs ditchable pockets for my new bc?

Thanks!

 

[bleeb]

You might want to have a look at the somewhat related current discussion on ditchable weight.

 

[SailNaked]

How buoyant do you want to be when you ditch your weight and why?

lets assume you want to ditch on the surface because you are performing a rescue depending on how you do that in a dry suit might answer your question.

or maybe

you are under the water in a rec environment, and you are ??? out of air? how long were you down, dumping weight at this moment might be a bad idea. you were after all neutral in the water at that point right? so why not just swim up or to your buddy.

if you answer the question of when you would ditch your weight it might answer your question.

edit: ok Flooded drysuit, failed BC, and too much weight all at the same time, would be a good reason to have ditchable weight.

 

[Garrobo]

I could never understand why anyone would ditch their weights except on the surface.

 

[muddiver]

If you need to ditch weight it will be because you need to be buoyant. It is really going to be a personal decesion based on experience and the buoyancy provided by your particular gear setup.

I would go with the 36 lb pouches because using the smaller pouches limits your ability to add weight if need. The pouches don't weigh 36 lbs, they are just big enough to hold "about" 36 lbs. You may find it hard to get a full 36 lbs in to them. If you have the smaller pouches what are you going to do if you can only really get 12 lbs of lead into them? Purchase for your cold water gear setup (i.e. weigh for dry suit) and then reduce the amount of lead in the pouch when you need to switch to warmer water diving.

 

[denisegg]

edit: ok Flooded drysuit, failed BC, and too much weight all at the same time, would be a good reason to have ditchable weight.

No, I've had a flooded drysuit and a BC hose that popped loose and I swam to the surface and orally inflated by wing. I had no ditchable weights because the only weight I was wearing was the doubles on my back.
You should be able to swim to the surface with the weight you are wearing or you need to make some adjustments somewhere.

 

[Mike Boswell]

How buoyant do you want to be when you ditch your weight and why?

lets assume you want to ditch on the surface because you are performing a rescue depending on how you do that in a dry suit might answer your question.

or maybe

you are under the water in a rec environment, and you are ??? out of air? how long were you down, dumping weight at this moment might be a bad idea. you were after all neutral in the water at that point right? so why not just swim up or to your buddy.

if you answer the question of when you would ditch your weight it might answer your question.

edit: ok Flooded drysuit, failed BC, and too much weight all at the same time, would be a good reason to have ditchable weight.

All good points. I would just add the possibility that YOU are being rescued, and the rescuer needs to remove some of your weight. Is it removable? Is it accessible? Will it be enough to get you buoyant?

 

[rstofer]

I could never understand why anyone would ditch their weights except on the surface.

The one scenario that keeps coming to (my) mind: a wetsuit diver with a full HP 100 diving at 100' and something goes wrong with the wing.

So, the diver finds themselves about 30# negative. With a lift bag or sizeable SMB, perhaps the problem can be solved. Otherwise, the diver has to ditch some weight or they will never get off the bottom. Their buddy with a similar 30# wing will be unable to help because their wing will be nearly 100% used just to achieve neutral buoyancy at 100'.

I'm not suggesting that dropping weight at depth is a good thing. But I am suggesting that wetsuit divers figure out how they will get off the bottom if their wing fails. Breathing up all the air in the tank to gain buoyancy might not be a good plan.

A diver needs to be several pounds positive just to get their head out of the water. I would think that there should be sufficient ditchable weight that a diver with a full tank and an empty BC could get their head above water even if their wetsuit is still partially compressed from the dive.

Always think of the rescue scenario: a random rescuer (not briefed in your specific equipment configuration) manages to get you to the surface. Their number one task is to get you positive without letting go lest you sink to the bottom. The easiest way to accomplish this is to drop a weight belt. It is easy to do from the front or rear. There is a question in my mind about ditching a weight harness from the rear.

In any event, I don't know how much weight should be ditchable. I would tend to look at 10# or more for cold water diving. Primarily because the wetsuit will still be partially compressed and less buoyant when the rescuer manages to get you to the surface.

The alternative of cutting away the rig or removing the BC just to achieve buoyancy seems like the kind of thing a random rescuer will find problematic. How do they keep your head above water while trying to accomplish this? Now, a highly trained and continually praciticing rescuer will have no difficulty but you might not get to choose.

As to drysuit configurations? Beats me... I don't have one so I haven't spent a single minute trying to figure out how best to accomplish the rescue.

Ditchable weight is all about rescue.

Richard