Why no weight pockets with doubles?

[PBcatfish]

Most assume that a double has to be much heavier and bulkier than a single.

It is not necessarily so.
The standard single here in Europe is 15 liters, 200 bars, carrying 3000 liters of air.
It is heavy and bulky, compared to an American 80 cft.
We have instead compact and streamlined 7+7 liters (or 8+8, 9+9, etc).
...

This is different from what I normally see in the US. I have not seen compact doubles or triples here, in more than 20 years. The doubles that I see here now are minimum 80 cf (11 liters?) each tank. I often see 100cf doubles & sometimes larger than that. I agree that skinny doubles are nice.

 

[Angelo Farina]

Doubles procedures were developed from technical or decompression diving where accidentally losing a weight is quite dangerous.

The whole concept of technical diving was unknown before 1990.
Doubles were in use as the standard air tank since the fifties, here in Europe, and they still were the standard until around 1985.
Loosing weights (or ditching them) was also quite common, as there was no BCD.
It seems that a lot of people is not aware of what was the situation some decades ago and draw conclusions based on unproven facts, such as the idea that a steel double is strongly negative buoyant.
It all depends on steel thickness, which is related to the standard pressure.
My first set was a 10+10 liters steel at 150 bars, and they were terribly floating. Even full of air they were sligthly positive. Each tank is different, and the choice of the kind of ballast to use and where to attach it must be evaluated case by case.
I really do not understand assumptions like "doubles are for tech diving", "diving doubles is tricky and requires special kills", or "doubles require an additional bladder"...
I made a number of dives with my 10+10 l steel doubles and no BCD.
I was a beginner, so within what today are considered recreational depths and times.
And my skills were poor.

 

[EireDiver606]

when would you use ditchable weights? just for surface use when you don't want to ditch the entire rig correct? Also, and just to clarify, when I see/hear ditchable weights I think of the recreational term for it of ditching at the bottom. Ditching while already at the surface is different, so may have just been a verbiage issue.[/QUOTE
Plenty of dir and gue divers use weightbelts. Its not non-DIR unless you don't need it. Think oceans.

 

[EireDiver606]

Oh - I forgot, that's the kool aide "Big Dive only Assoc."

Dude. What is this comment. What is the hate for.

 

[tbone1004]

Plenty of dir and gue divers use weightbelts. Its not non-DIR unless you don't need it. Think oceans.

I use a weightbelt when necessary as well, but if you go back to my second post on this thread, I don't really consider weight belts "ditchable weights" in the way that the industry usually defines them. They usually define ditchable weights as something that you ditch at the bottom in the event of equipment failure. I have no intention of ditching a weight belt when I wear one. Sure if I'm stuck at sea and my BC has failed I'll ditch it to avoid shedding the entire rig, but that's not what the industry is usually talking about when the term "ditchable weight" is used.

 

[EireDiver606]

Having to use a dry suit with doubles is a sign of a lack of skill not because of safety

Thats a load of horse ****.

Diving a dry suit needs more buoyancy skill than a wetsuit. If its warm use al80s with a wetsuit. If its cold, use steel 12l twinset with a drsyuit.

 

[EireDiver606]

I use a weightbelt when necessary as well, but if you go back to my second post on this thread, I don't really consider weight belts "ditchable weights" in the way that the industry usually defines them. They usually define ditchable weights as something that you ditch at the bottom in the event of equipment failure. I have no intention of ditching a weight belt when I wear one. Sure if I'm stuck at sea and my BC has failed I'll ditch it to avoid shedding the entire rig, but that's not what the industry is usually talking about when the term "ditchable weight" is used.

Agreed. FYI in the technical industry "ditchable weight" is anything that can be ditched.

 

[tbone1004]

Agreed. FYI in the technical industry "ditchable weight" is anything that can be ditched.

I'm aware, I teach technical courses.... but this is in a recreational subforum

 

[AfterDark]

Thats a load of horse ****.

Diving a dry suit needs more buoyancy skill than a wetsuit. If its warm use al80s with a wetsuit. If its cold, use steel 12l twinset with a drsyuit.

Maybe for you more skill is required to dive dry. I don't see where it does. I've been diving dry suits since 1970something.

 

[AfterDark]

I'm aware, I teach technical courses.... but this is in a recreational subforum

If a weight can be released and dropped it's ditchable what does rec or tech have to do with it?