How much ditchable weight is best?

[jonnythan]

You would have been able to get back to the surface, but the last, oh, 70 feet or so of your ascent would have been uncontrollable and you would have hit the surface like a Polaris missle.

This is the big problem with thick wetsuits when deep. There is no way to avoid being horribly overweighted at 100+ feet because the suit will compress so much.

As for the non-DIR answer, carry some ditchable weight, but not a whole lot. If you only drop 5 pounds or so you *might* be able to swim it up at depth and have some shot at controlling your ascent.

 

[VTernovski]

What you are saying makes a lot of sense. But, here I am remembering being at 120 feet and sinking

probably not a good idea to be at 120 ft on AL80 in the first place ;-)

 

[MaxBottomtime]

The only ditchable weight I carry is a 2# HID light. If I can't ascend without ditching two pounds, I must have just had my arms and legs bitten off by a shark. In case of wing failure I have two backups; my drysuit and liftbag. Also, you should strive to be neutral at 20 feet with a near empty tank, not at the surface. You want to be able to control your buoyancy so you can make deco/safety stops. At the surface, you can use your wing/BC for positive buoyancy.

 

[OneBrightGator]

Somewhere between 10-25% is a decent amount.

I put half my weight in trim weight pockets on my upper camband and the rest in a weightbelt, trims out great and gives me some ditchable.

 

[Daryl Morse]

Also, you should strive to be neutral at 20 feet with a near empty tank, not at the surface. You want to be able to control your buoyancy so you can make deco/safety stops. At the surface, you can use your wing/BC for positive buoyancy.

If you're neutral at 20 fsw with a near empty tank, then you'll be positive if you ascend. I don't know about you, but I can feel the buoyancy difference as I go from 20 fsw to 10 fsw. Sometimes my drysuit neck seal even burps out some residual air as I slowly ascend through 10 fsw. I like to be able to control my ascent all the way to the surface. I'd rather be neutral at the surface than at 20 fsw.

 

[Curt Bowen]

You should be able to swim your rig up from depth in the event of a total BC failure.

What if your wearing double steel 125's and a stainless backplate?

 

[jagfish]

What if your wearing double steel 125's and a stainless backplate?

Not that it's a huge difference, but wouldn't an AL plate be a better choice for this configuration...?

 

[Reinoud]

What if your wearing double steel 125's and a stainless backplate?

That is the reason why you should wear a drysuit if you dive with steel doubles....
Steel doubles + wetsuit is not considered DIR

 

[Reinoud]

Somewhere between 10-25% is a decent amount.

I put half my weight in trim weight pockets on my upper camband and the rest in a weightbelt, trims out great and gives me some ditchable.

When I dive single tank and cannot use a V-weight, I control my trim by putting some soft-lead pockets inside the channel of my backplate. I can put up to 3 kilo in there

 

[Reinoud]

If you're neutral at 20 fsw with a near empty tank, then you'll be positive if you ascend. I don't know about you, but I can feel the buoyancy difference as I go from 20 fsw to 10 fsw. Sometimes my drysuit neck seal even burps out some residual air as I slowly ascend through 10 fsw. I like to be able to control my ascent all the way to the surface. I'd rather be neutral at the surface than at 20 fsw.

Normally you are. If you dor Rock Bottom planning you will never ascent with a near empty tank under normal conditions