Only ONE tank...

[NamTinker]

Tom
In the early stages of a dive, within rec limits of 40m, could you easily swim to the surface in case of wing failure?

 

[Tom Winters]

I'm only 10-pounds negative at the start of the dive - dropping in and not kicking, I just float down to the bottom. If I had to, I can do a free ascent from at least 80' since I've done that before. And, if my wing did fail - my beloved Oxycheq fail??? - I have enough gas to leisurely stroll in underwater from 40 meters deep on any part of the US east coast continental shelf.
I used to go on underwater walks in Oahu - I'd strap on three 12-pound weight belts, no wetsuit, fins clipped off to the bc,and an aluminum 80. My favorite spot was the Haleiwa Trench where there was a sheer drop from 15' down to 110'. Sometimes I'd crawl alongside the wall - like being on a liquid moon. The hike back to the car was always tough though.

 

[StSomewhere]

Only ONE tank, huh?

I'm personally in the process of buying a pair of the elusive E7-100s. But in spite of that I keep second guessing myself, mostly because the E8-130 holds almost as much gas as two AL80s. Someone check my math here:

If the E8-130 holds a true 130 cf at 3442 psi then at 500 psi you'd have used +/- 111 cf. Compare that to an AL80 which holds a true 77.4 cf at 3000 psi, so breathed down to 500 psi you'd have used +/- 64.5 cf. per tank. Multiplied by two tanks, a pair of AL80s gives you a best case of 129 cf of usable gas. So for the one big tank you get almost as much usable capacity (86%) as with two AL80s, but you can still use it for long nitrox dives, and no need to go back to the boat or shore. Geez, I may have just talked myself out of the E7-100's again.

Seems like E8-130 is popular on this board, but I'd hate to be hauling that 43 pound monster through heavy surf.

E7-100 at 33 pounds, 1 pound negative empty, looks pretty good to me. Lots more air than I normally use, and not a back breaker.

And at 43 lbs, its still lighter out of the water than doubled AL80s (or doubled anything else), and its the same length as an AL80. You are right that 43 pounds plus weights, etc. would be a lot to schlep around out of the water.

 

[NamTinker]

Damn! With all this talk I somehow ended up ordering two E8-130's. I was thinking about one single tank. It somehow became TWO. Must be how nitrogen narcoses feel... because I can't remember... And now the snowball has started downhill - twinning bands - manifold -rubber knobs... HEEELP!

 

[Lil' Irish Temper]

I'll be the odd-ball here - PST LP 104

Whadda mean they don't make them anymore.

 

[teknitroxdiver]

nah not really an oddball. a -130 is basically a 104 that is legal to fill to 3442.

 

[BEM]

E-7 100 for me (currently 80 Al) and
E-7 80 for my wife (currently 63 Al).

 

[joedelt]

FWIW, i bought E8-130s and they finally came in.
i like the idea of having plenty of gas and that if i decide to go technical, i've already bought the big expensive ones so if i needed more i can either get more of the same, or smaller (hopefully)cheaper ones