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View Full Version : Twinset - Fine tuned buoyancy; adding 2kg for the 2nd dive?



ManualOverride
05-09-2018, 02:26 PM
I've seen a couple of people do this now and it's just madness to me so I thought I'd post about it...
On a 2-dive day with twinsets, my buddy tells me on the 2nd dive buddy check about some extra weight or a weight belt which wasn't present on the first dive.
They were going in on the fist dive with enough weight for half full cylinders, but not enough to keep them down when empty.

Does anyone else do this?

If I had a manifold or 2nd stage failure at the ascent time of dive, I can easily see myself losing a quarter of my gas before shutting down completely, even with a perfect shutdown drill.
I weight myself for empty cylinders on every dive, it means I'm overweight on the first dive of the day but to me it's better than risking over-buoyancy during an incident.

jb2cool
05-09-2018, 02:35 PM
Never heard of that before.

So on the first dive if their plan went tits up of they needed to donate gas to a buddy and used more gas than expected they might not have enough weight? Seems like a bad idea to me.

Ian_6301
05-09-2018, 02:40 PM
Agreed. Shit plan....


Although I have forgotten a weight belt and cuffed the first dive without one in the past, and worried about it all dive.

WFO
05-09-2018, 02:42 PM
Shit plan but if it's no deco stuff, probably not going to kill them.

ManualOverride
05-09-2018, 02:42 PM
Never heard of that before.

So on the first dive if their plan went tits up of they needed to donate gas to a buddy and used more gas than expected they might not have enough weight? Seems like a bad idea to me.

Yup - It's the 2nd person I've come across with the same idea! First person missed a stop because they forgot to add the weight on the 2nd dive. :shake:

ManualOverride
05-09-2018, 02:51 PM
Agreed. Shit plan....

Although I have forgotten a weight belt and cuffed the first dive without one in the past, and worried about it all dive.

Ha - that is a horrible feeling... When I dived with a belt I would usually remember it during buddy check and have to do the shuffle-of-shame as I try to thread it through my crotch strap and under my back plate while my buddy rolls their eyes.

Sounds like there is no good reason and no reasonable mitigation for this, glad I wasn't missing anything... Hopefully it will dissuade anyone else form having the same bright idea.

Nickpicks
06-09-2018, 01:51 PM
That sounds a bit farm animal stupid to me. If they have a problem that means they lose all their gas, go on to sharing a buddy's gas, but then can't hold a stop.

nigel hewitt
06-09-2018, 02:13 PM
I've had this nonsense from a very 'senior' diver in our club.
"It works for him", "it's obvious" and "I worry too much".
This is the same guy who was too light at 6m and I ended up unwinding his DSMB line from his gear so we could get him back in the RIB.
I think he thought that was my fault too because 'rebreather'.
He has asked how much extra deco he's going to have to do with me on the rebreather when I read the profile as no-stop.

ManualOverride
06-09-2018, 02:39 PM
That sounds a bit farm animal stupid to me. If they have a problem that means they lose all their gas, go on to sharing a buddy's gas, but then can't hold a stop.

I think next time I'm going to have to explain they can't dive that configuration as I only have a 6' octo, and I need it to be at least 5m for the 'light on the fist dive' setup so they can breathe all the way the the surface. :grin:


I've had this nonsense from a very 'senior' diver in our club.
"It works for him", "it's obvious" and "I worry too much".
This is the same guy who was too light at 6m and I ended up unwinding his DSMB line from his gear so we could get him back in the RIB.
I think he thought that was my fault too because 'rebreather'.
He has asked how much extra deco he's going to have to do with me on the rebreather when I read the profile as no-stop.

Excellent - I was beginning to think I was the only one who had experienced this! Where did this idea come from?

WFO
07-09-2018, 01:26 PM
I think next time I'm going to have to explain they can't dive that configuration as I only have a 6' octo, and I need it to be at least 5m for the 'light on the fist dive' setup so they can breathe all the way the the surface. :grin:


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