Steel tanks & wetsuit - some real experience to go with the claims....

[ElectricZombie]

Genesis once bubbled...
It is more likely that I will accidentally ditch a belt than have a complete buoyancy system failure. I've seen several inadvertant ditches in the last year, but no total BC failures. So the proposed "DIR" solution trades a very unlikely failure for a more-likely failure, and the latter one can kill you just as dead (especially if you have a deco obligation when it happens!)

If you are worried about a weight belt coming off, you might want to try a channel weight. It is a piece of lead that fits in the recessed channel of the BP.

I rarely ever wear any additional weight with my BP/Wings setup, but when I do, I use a weight belt that has 2 metal buckles. I would balance the rig so that only a small amount of weight needed to be on the belt.

 

[jonnythan]

ElectricZombie once bubbled...


If you are worried about a weight belt coming off, you might want to try a channel weight. It is a piece of lead that fits in the recessed channel of the BP.

I rarely ever wear any additional weight with my BP/Wings setup, but when I do, I use a weight belt that has 2 metal buckles. I would balance the rig so that only a small amount of weight needed to be on the belt.

But then he couldn't ditch that weight and it would be no different from just wearing heavier tanks.

I find this whole thread very interesting. I think the answer is to go with the Al 80's and a few pounds on the weight belt... wear a belt with the 8 or 10 pounds necessary to compensate with a SS buckle under the crotch strap and I don't think there would be any issues.

 

[ElectricZombie]

jonnythan once bubbled...

But then he couldn't ditch that weight and it would be no different from just wearing heavier tanks.

The key is to have a balanced rig. If the rig is balanced properly, there is no need for ditchable weight. If a rig is balanced, you can swim it up from the bottom at all times, even with a failure.

I dive AL doubles with a steel BP when wet and no additional weight. The SS BP adds just the right amount of weight to properly balance the rig. I can swim it up at all times so, ditchable weight is not needed.

 

[jonnythan]

ElectricZombie once bubbled...


The key is to have a balanced rig. If the rig is balanced properly, there is no need for ditchable weight. If a rig is balanced, you can swim it up from the bottom at all times, even with a failure.

So how would you balance his rig? With full Al 80s on his back and a channel weight, how negative will he be at 90 feet in his wetsuit?

 

[ElectricZombie]

With double 80's, he can probably just use a SS BP with no additional weight and be pretty well balanced. You should not need a channel weight when wet using 80's. Depends on his exposure protection though. If he dives a drysuit, then he might have to add the channel weight.

 

[jonnythan]

ElectricZombie once bubbled...
With double 80's, he can probably just use a SS BP with no additional weight and be pretty well balanced. You should not need a channel weight when wet using 80's. Depends on his exposure protection though. If he dives a drysuit, then he might have to add the channel weight.

You didn't even read the original post did you?

The question is how negative will he be at 90 feet with double Al 80s? Once you figure out the answer to that, decide if he's going to need to have some weight ditchable.

 

[Genesis]

swim up double HP100s, full of Nitrox, in a 3 mil full wetsuit on an AL plate from 120'.

No problem at all.

I dive that configuration with no ditchable weight.

 

[Padipro]

Genesis once bubbled...
Config was a SS BP, double HP100s, 500 psi of gas, 3 mil wetsuit, booties, and the usual mask, fins, etc. Wing is an Oxycheq 70.

Now the general rubric is that you don't dive steelie doubles in a wetsuit. The argument goes something like this - a complete BC failure will kill you.

Hmmmm.. will it?

Let's see where I ended up.

With no gas in the wing, and the tanks at 500 psi, I was just slightly negative at the surface. So, I can stay down when low on gas at any depth from max to zero.

I needed no belt.

I find it hard to believe that you can be so positively buoyant with this rig even with only 500 PSI in the tanks. I'm using double 3300 PSI AL 90's with an AL BP and a new 5 mil semi-dry suit in the ocean with no added weight and I sink like a freakin rock even with the tanks near empty.

Scott

 

[100days-a-year]

I believe the 90s to be about -7 each full.Hard to find any lit on them as they were a small run for a short time.BTW,I have swum up full lp95s with a SS B/P and no rubber during the summer.It wasn't fun but I'd forgotten my stringer and I wanted to see how difficult it was.The HPs are less negative so I doubt it would be that hard.

 

[Genesis]

are neutral to slightly negative empty.

So are HP100s.

Now LOW PRESSURE tanks are major negative empty, and with those I'd have a problem.

I do NOT like being overweighted - beyond the obvious dangers, it makes trim nearly impossible to get right.