tank and boyancy logic, am i correct with this?

[piikki]

i'd point out another issue...
it's hard to figure out how things trim without being able try something. Your height (physical height of the diver) does make a difference when choosing tanks. I was at the same point as you a year ago - I needed to get weight off because of my back and shore dives. I went with HP80s... only to realize the tanks were way too short for me later. I could not trim them (I was always head-heady). Wisened up from my mistake, I bring up apiece of advise that I did not get when buying - if you are tall, avoid very short tanks. HP80s are fairly short.
If you are unable to trial I second the HP100 (or LP85) both very easy to trim according to various size divers I've met.

 

[dannobee]

The HP 100s are really nice tanks to carry around. They're lighter than my 95s, smaller on your back, and take lead off your waist compared with an Al80. But they're expensive.

I have a couple of HP100's, three LP95's, a couple of HP80's, some HP120's and a bunch of AL80's. I really like the HP100's, but there's that little problem with getting decent fills with them.

They're pretty negative, so he could take even more weight off of his belt if he uses the Faber HP100's. I paid $100 for the pair of HP100's, but they needed hydros, FWIW. Look around, you might be able to get a good deal, too.

If I'm worried about getting a good fill (say, off of a boat or a more remote area), I'll take the LP95's.

If you're a bigger guy, size isn't as important, although if I'm diving a remote site (like Moby Ling Cove in my picture gallery), I'll dive with the HP80's because they're lighter.

 

[CompuDude]

Cody, if you're average-sized or taller, I'd say go for the HP100. If you're on the short side, then perhaps consider the HP80. The weight savings with the 80 is barely better than the 100, but you get a lot more gas with the 100, even if you can't get a full fill. Assuming you're currently diving Aluminum 80s, you'll still end up with a smaller, and perhaps a smidge lighter, tank, because Al.80s and HP100 are very nearly the same size and weight.

I love the big, honkin' HP119, 120, 130's, but those suckers are immensely heavy to haul down to the dive site, IMO. Good if you own a lot of tanks and can pick and choose for the given dive site, but I think the HP100 is better overall for most conditions, while the bigger tanks are only better in some conditions. Oh, and they're a LOT more money.

 

[TSandM]

The LP 95 is a nice tank, too -- That's what I dive. Much cheaper than the HP tanks, you can get a good fill anywhere, and if you're lucky, more than that And if I can haul them around, anybody can.

 

[CompuDude]

The LP 95 is a nice tank, too -- That's what I dive. Much cheaper than the HP tanks, you can get a good fill anywhere, and if you're lucky, more than that And if I can haul them around, anybody can.

True, those are nice tanks with some genuine advantages. A little big and heavy, though, IMO... 8" vs. 7.25, and 38 lbs vs. 33 lbs. Great way to carry a lot of gas, though, since they're so easy to fill (and overfill). I just prefer the hp100's since they're nice and small, and still offer a lot of gas. Very easy transition from Al.80s, too.

 

[limeyx]

The HP 100s are really nice tanks to carry around. They're lighter than my 95s, smaller on your back, and take lead off your waist compared with an Al80. But they're expensive.

That's why i got the LP80's for 1/3 the price and get them overfilled to 32-3400.

Ooops, did i say "me" -- I meant "a friend" does that.

The 119 is a nice tank too, but then you may as well go to the 130

I use the 80's for dives where I have to carry the tank down a cliff or for a long distance, or the dive is very shallow.

119's for everything else (boats, deep shore dives) and probably will just get the 130 next.

 

[divemaster_jim]

The LP 95 is a nice tank, too -- That's what I dive. Much cheaper than the HP tanks, you can get a good fill anywhere, and if you're lucky, more than that And if I can haul them around, anybody can.

Another vote for the Faber LP95's, To me it's a good tank, got 2 for $520.00
I use 104's for doubles, even as a single tank a 104 is a bigger bear than a LP95 or a HP100.

 

[skynscuba]

You need to go back to Archimede's law an "an object is buoyed by the weight of what it displaces" a Worthington 80 displaces less than an aluminum 80. If for example the Worthington displaces 35 lbs of water 30(tank) -35(water) the answer is -5 lbs.
If an aluminim displaces 40 lbs of water (it is bigger than a steel HP80) and weighs 35 lbs it is 5 lbs positive 40 (water) -35 (tank)=+5.

Even though both tank weigh the same the buoyancy characteristics are different.

Like I said, I hope that this XS-80 tank is negative 5 when empty, rather than the minus 3 advertised, since this tank is about 2 pounds heavier than advertised. Otherwise the total weight climbing up after a dive is more than advertised. Still ~9# better than the AL80, but ~10.9 is advertised (7 buoyancy, 3.9 tank weight). With my hip and knee, I can feel that 2#.