Ditchable weights / balanced rig

[lexvil]

When you say 'heavy plate', what weight is it ?

9.5lb, it’s a one off that Eric made just to know he doesn’t want to make them that heavy. I added 7lb under the rail.

 

[Subcooled]

Question 1: How ditchable should weights really be?

It depends.

Once you start to dive in caves (or under ice) you do NOT want ditchable weights. You loose those by accident, and you'll be pinned in the ceiling, which might suck... A redundant buoyancy compensator is the way to go. Read: wing and drysuit, or double bladder wing, depending on water temps.

In open water you will need either
- redundant buoyancy (better), or
- ditchable weights (the panic option)

If you ditch you weights then your ascent will be an uncontrolled one. No safetystop. No decompression stop. Nothing. Up you go. It's fine on shallow dives. Once you dive deeper, you will want staged decompression, in which case you want to keep your lead but inflate some buoyancy device instead.

Whatever solution you choose, please keep in mind that you will need TWO ways of getting to the surface. In some cases that ascent needs to be a controlled one, in others, it really doesn't.

Ways to return to the surface:

1. ditch some weight (a brutal solution)
2. use a secondary buoyancy compensator (controlled)
3. optimal weighting: used OC gas (=lost mass) forcibly makes you buoyant (brains needed; do not get it wrong)
4. pull yourself up by a rope (desperate)
5. someone pulls you up (commercial and public safety divers)
   
6. "Oh, I have a DPV"
7. Previously unknown forms of buoyancy

 

[Raphus]

It depends.

Once you start to dive in caves (or under ice) you do NOT want ditchable weights. You loose those by accident, and you'll be pinned in the ceiling, which might suck... A redundant buoyancy compensator is the way to go. Read: wing and drysuit, or double bladder wing, depending on water temps.

In open water you will need either
- redundant buoyancy (better), or
- ditchable weights (the panic option)

If you ditch you weights then your ascent will be an uncontrolled one. No safetystop. No decompression stop. Nothing. Up you go. It's fine on shallow dives. Once you dive deeper, you will want staged decompression, in which case you want to keep your lead but inflate some buoyancy device instead.

Whatever solution you choose, please keep in mind that you will need TWO ways of getting to the surface. In some cases that ascent needs to be a controlled one, in others, it really doesn't.

Ways to return to the surface:

1. ditch some weight (a brutal solution)
2. use a secondary buoyancy compensator (controlled)
3. optimal weighting: used OC gas (=lost mass) forcibly makes you buoyant (brains needed; do not get it wrong)
4. pull yourself up by a rope (desperate)
5. someone pulls you up (commercial and public safety divers)
   
6. "Oh, I have a DPV"
7. Previously unknown forms of buoyancy

I agree 100%
I dive dry with non ditch able weigths..

But now I wonder what to do, when diving wetsuits. There is no way to swim up the buoyancy of a compressed 5 mm or worse 7mm suit.

So on holiday diving wet, I want to have some weigths ditchable..
Is there any good way of doing this?
I have a lot of experience diving dry and cold water, but wetsuit and warm water is something I am not used to.

 

[Subcooled]

I have a lot of experience diving dry and cold water, but wetsuit and warm water is something I am not used to.

A shared experience indeed.

A skilled and composed diver can certainly open a weight belt (those suck, I know) and drop 2 lbs at a time, unless it's an uncontrolled plunge towards -100m/-300ft... I haven't tried it in a real situation, so do not blame me it it fails.

Freedivers use 2kg neck weights. Those are easy to dump. Have you tried?

 

[Raphus]

A shared experience indeed.

A skilled and composed diver can certainly open a weight belt (those suck, I know) and drop 2 lbs at a time, unless it's an uncontrolled plunge towards -100m/-300ft... I haven't tried it in a real situation, so do not blame me it it fails.

Freedivers use 2kg neck weights. Those are easy to dump. Have you tried?

Jeah, maybe a little pocket, like used for trim weigths.

 

[Subcooled]

Jeah, maybe a little pocket, like used for trim weigths.

Sounds good. Let us know how it worked. I'm quite interested.

 

[Raphus]

Sounds good. Let us know how it worked. I'm quite interested.

Jeah I though that might be a good solution. So I can just drop 1 kg and maybe another pocket with 1 more.

I don't like any pockets or belts that can drop by accident..

 

[inquis]

2. use a secondary buoyancy compensator (controlled)

Under this category, I'd put

a. use a buddy's help
b. use a DSMB
c. secondary bladder in your BC
​

You just need to get "over the hump", since it gets easier as the wetsuit expands. Limiting depth is another option, as that lessens the wetsuit buoyancy loss and therefore the difficulty in swimming up.

 

[troponica]

Few things for a BP+wing...

• The harness; just go for a simple one-piece harness. €50 or thereabouts. You don't need breaks in the harness.
• The backplate: stainless steel 3mm is normal and gives you a couple of kg of weight. Aluminium is lighter (maybe good for flying, or if you're wearing heavy kit in fresh water). Generally use stainless steel. €50 second hand - you don't need new.
• Wing: need two; one for a single with about 15kg buoyancy, one for a twinset with about 18kg. They're different as the twinset version is wider. Get a doughnut wing, NOT a horseshoe. Don't get a bungeed one. Lots of options around; Halcyon's the most expensive, but there's plenty of others which are just as good.
• Single tank adapter: required if using a single tank. This is a U-shaped metal plate and a couple of cam bands. You should get 4 weight pouches to put on the cam bands to put your weight. (The number depends on how much weight you need and where you put it). About €50 second hand.
  
• Weights; for single tank use weightbelt weights. For a twinset you will use 'V' weights which fit behind the twinset between the wing and backplate. Would suggest you get a "tail weight" too. Get 5 kg in 2kg, 1kg and a 2kg tail weight.

Got a DIR harness to see if I like it, if not, I'll just add one QR. Apeks WTX-D30 w/ ultralight travel plate, usually no weight pockets needed (mostly using rash guards and also switched to a sharkskin to replace the 3&5mm). Cam bands w/ trim pockets just in case.

All in all, the setup should be at around 2.1-2.3 kg, which is 700-900g lighter than the Hydros.

For local diving in 7 mm or semidry / single tank I'll just get a regular steel bp, same wing. For doubles, haven't decided on a wing yet...

 

[troponica]

It depends.

Once you start to dive in caves (or under ice) you do NOT want ditchable weights. You loose those by accident, and you'll be pinned in the ceiling, which might suck... A redundant buoyancy compensator is the way to go. Read: wing and drysuit, or double bladder wing, depending on water temps.

In open water you will need either
- redundant buoyancy (better), or
- ditchable weights (the panic option)

If you ditch you weights then your ascent will be an uncontrolled one. No safetystop. No decompression stop. Nothing. Up you go. It's fine on shallow dives. Once you dive deeper, you will want staged decompression, in which case you want to keep your lead but inflate some buoyancy device instead.

Whatever solution you choose, please keep in mind that you will need TWO ways of getting to the surface. In some cases that ascent needs to be a controlled one, in others, it really doesn't.

Ways to return to the surface:

1. ditch some weight (a brutal solution)
2. use a secondary buoyancy compensator (controlled)
3. optimal weighting: used OC gas (=lost mass) forcibly makes you buoyant (brains needed; do not get it wrong)
4. pull yourself up by a rope (desperate)
5. someone pulls you up (commercial and public safety divers)
   
6. "Oh, I have a DPV"
7. Previously unknown forms of buoyancy

Starting with an Intro to Tech in a couple of months, followed by Cavern/Intro to Cave. Most probably wing and drysuit.

As for ways to return to the surface, if I have a choice, I'll go with 2 and 3.