Neutrally Buoyant Al 80's

[JeffG]

I wouldn't need some obscenely big v-weight to get them down like i would with the standard double al80s...

What?? 6 lbs is obscenely big?

 

[DIR-Atlanta]

OTOH, i've been thinking about a set of double al80s to compliment my existing steel doubles and the neutral 80s would be cheaper than double LP80s or double HP100 steel tanks, and I wouldn't need some obscenely big v-weight to get them down like i would with the standard double al80s...

I haven't done a lot of comparison shopping, but from what I have seen, the cost of double S080s + V-weight is about the same as the cost of double NB80s. Furthermore, if you have multiple sets of double S080s, then you only need one V-weight, whereas multiple sets of NB80s will cost you $30-40 more per set for every set that you purchase. Advantage: S080s

The dry weight of double S080s + V-weight is about the same as double NB80s. Advantage: Equal/None.

Standard S080s can be used as stage bottles or as doubles, NB80s cannot (or perhaps I should say "should not" ). Advantage: S080s.

Not to mention that is easier to get S080s filled to capacity vs NB80s. In fact, some places are charging extra now for fills in excess of 3000 PSI, so in many cases S080s are cheaper to fill for the same amount of gas.

Standard S080s are less expensive, more versatile, and more cost effective in the long run. For my money, they're really the only thing that makes sense in this situation.

 

[jfoster33702]

I would think that the ability to pump them to 3300 would be an advantage?

Jeff

 

[Dan Gibson]

Why? It's still the same volume, 80 cft.

I would think that the ability to pump them to 3300 would be an advantage?

Jeff

 

[jfoster33702]

Im brain-dead. Just realized that they make it heavier by replacing volume with metal..

 

[1amphibian]

Glad you had this thread, I was curious about the exact same thing today, great info, I won't be looking at the NB80's now, will stick with the regular 80's.

 

[Dan Gibson]

It happens to all of us at times.

Im brain-dead. Just realized that they make it heavier by replacing volume with metal..

 

[SDAnderson]

I've owned a couple of NB80's for the past five years and haven't sold them yet. Used as singles, they allow you to take a few pounds off the weight belt and I haven't had a problem with the trim. Actually, I'd rather dive them than S080's when diving on a single cylinder but its not important enough to get lathered up about, either way. Doubled up, they work okay although you may need to fiddle to get the pitch axis balanced properly - I consider that to be SOP for any doubles. As deco bottles, they're too negative and don't make the grade.

Of course, your results may vary: I dive cold water which means drysuits, heavy underwear and lots of bouyancy and single-tank diving that requires enough ballast to trim out most anything. I'm also not slavishly DIR and willing to occasionally risk the :mooner: opprobrium of my friends.

 

[Marlinspike]

I have been diving NB 80s doubled as my ocean rigs for about 4 years or so. I dive NC wrecks with them almost exclusivly but I dive E8-130s when I need more gas or in fresh water. The E8s are very top heavy so I don't feel the added wieght of the NB80s at all in that respect. I really like the setup with a 6lb SS backplate.

My opinion is that these tanks actually help maintain proper trim and body position closer to what I would be like with the E8s, which I use far more often. The NB 80s are nowhere near as topheavy as people here seem to imply. My biggest issue has been getting them filled to service pressure by dive operators who think they are normal 80s.

I use normal AL 80s for my stage bottles.

~Marlinspike