having some trouble deciding on tank size

[halocline]

Those are pretty big tanks. Personally, I like diving with the smallest tank I can for the particular dive I want to do. A HP100 (SP, 3442 PSI) is a pretty versatile tank that won't break your back. I also can't imagine diving much with a single 130; to me if I'm on a dive where I need that much gas, it's likely to also be a dive that I want some redundancy on. IOW, a pair of 72s would be much more useful to me than a single 130, even though there's not much difference in total gas. Something to think about....

 

[aquaregia]

Unfortunately it costs twice as much to fill my double 72s

 

[Bogie]

HP100's is the sweet spot. With any HP tank you must have a good dive shop that gives you full fills and not hot fills.

 

[tbone1004]

Nice thing for us with the single 130 is it allows us not to change tanks out when we're doing dives with students. Our SAC rate is MUCH lower, so when they're switching their 80's out, we can leave our rigs set up and not have to worry about it. Easier than us diving doubles and them in singles and what not to have similar rigs set up and going.

 

[Edward3c]

I must be turning into a dinosaur.

When I started diving we used to plan to use the correcr size tank(s) to complete the dive, surfacing at our chosen resurve (then 30bar - I said I an a dinosaur).

The number of people I dive with who finish a dive with more that 50% of the gas they started with is getting comical. Also many don't understand the bouyancy characteristics of useing gas.

Regards

 

[Dave616]

HP100's is the sweet spot. With any HP tank you must have a good dive shop that gives you full fills and not hot fills.

Agreed.
I own two HP 119's, one HP 100, and one HP 80. All four are XS/Worthington.
The HP80 is the most fun to dive, but I'll be investing in about three more of the
HP 100's. I wish I would have just bought four HP 100's the first time around.

 

[halocline]

Nice thing for us with the single 130 is it allows us not to change tanks out when we're doing dives with students. Our SAC rate is MUCH lower, so when they're switching their 80's out, we can leave our rigs set up and not have to worry about it.

I guess, but what's more trouble, switching tanks between dives or lugging around a big tank on land and in the water?

I do the majority of my dives with 72s and AL63s, but most of my local dives are pretty shallow and I'm pretty good with air. It's more fun to dive with a small tank. I use my HP100 for deeper dives and the doubles when I need to, or specifically for practice managing doubles.

I'm curious about the HP80 which is really tiny, and I suspect my curiosity will eventually lead me to buy yet another scuba tank...

 

[halocline]

Unfortunately it costs twice as much to fill my double 72s

Sad but true....and when you get a short fill it's twice as annoying.

 

[Couv]

I'm curious about the HP80 which is really tiny, and I suspect my curiosity will eventually lead me to buy yet another scuba tank...

But you already own several hp 80ies. A good old 72 filled to 2800.

 

[tbone1004]

But you already own several hp 80ies. A good old 72 filled to 2800.

the HP80's are actually really nice if you're not gargantuan... I have a few and can't use them because they're too short. Trying to trade them for LP85's or something similar...