Long/thinner tanks - ideal for cave diving??

[Moonfuzzy]

Hmm, sounds just like what I'm looking for, but are these AL or steel tanks??

They are steel tanks.

I can notice the differance when I swim my tanks vs 95's, and mine are lighter - big bonus for me. (the 100's are more comparable to LP 85's in volume) When I dive 104's I feel like I am driving a semi!

Where you really notice a differance is in tight cave.. I think that the diameter is like 1" or so smaller, which doesn't matter in Ginnie mainline but that makes a big differance in the Wormhole ; ) You have more clearance, so you can dive cleaner and make no contact - what we should all be striving for ; )

I do agree with the comment about improving technique. If you already own tanks I don't know if it is really worth it to buy new ones for the streamline affect... technique and trimming gear out will get you far with much less coin.

I have NEVER had a problem getting a fill for my tanks to rated pressure in cave country. Outside of the area I have been impressed.. maybe I am using tech-friendly shops but I have not really had problems getting fills to 3500 in the Keys or West Palm.

Pressed Steel HP-100s are identical to their LP-80s except for the size of the necks. They are a tad smaller and a tad heavier than Faber LP-85s.

The diameter of the HP-100s and HP-120s is 7.25 inches - the same as aluminum 80s.

[BillGraham]

Technique and trim are about 100x more important. Ditch the danglies, streamline, get horizontal, find the shadows in the flow, Pull and Pull when appropriate, and be as comfortable and chilled out as possible. You'll get the results that way much faster and cheaper.

Good Luck, Drew

Yup, that's the ticket. I got shot out of there like a cannonball until my friend showed me where to go to stay out of the flow. As you dive more, ducking into the "shadowed" areas becomes second nature.

I know that you've got a lot to figure out right now but you might look at sidemount down the road if you're really interested in streamlining. I personally don't think tank size has much to do with anything once you're in the water. The amount of gas in your wings is probably more significant so getting your weighting dialed in is the best first step.

[Cindy]

Boy, I wish Bill Main would post! He would have something to say about sidemount "improving" streamlining. Most sidemount divers are far from streamlined. I love sidemount diving because it's easy on my back and I can get into tiny caves but backmounting is what I do in large high flow caves and I need to use multipal stages and scooter. It's just easier and I don't have to worry about even more stuff hanging off my chest. Learn technique first. Then go with what gear you used in class until you are comfortable with diving in caves. Learn how to be a great swimmer first and scooter later, you will save your life some day. Then learn how to adjust the gear you have to the cave that you want to explore. You will be a better and more flexible diver. If you learn to adapt, think problems through and remain calm you will last a lot longer at cave diving than thinking up little details about the size of tanks. I know you guys are bored. I'm pretty sick of work and ready to get outdoors and do some diving myself. Have a good one, Cindy Butler

[andrebasso]

That kind of makes sense, staying in those low flow area where the eddies are formed by the current. Good advice guys. Guess I have lot's to practice... back to the tanks though, I realized it really isn't so much the tank diameter but the weight of the tanks. If you have tanks that are perfectly weighted for you, then you'll have the minimum amount of air in the BC. Thinking back on my trip to Ginnie - my wings were inflated like a balloon. Those old PST 104's I was renting were made of pure lead. I definitely need lighter tanks.

[D1V3R]

didnt poseidon come out with a doubles system based on 2 low profile tanks?
I think each tank was only like 60 cu. ft. though, so you would be better off with a single 120 in that case.
that would probbaly be good for sump diving, like as an extension to side mounting because tank size is so limited (unless you're 7 feet tall, lol)

[Arnold Mesiser]

didnt poseidon come out with a doubles system based on 2 low profile tanks?
I think each tank was only like 60 cu. ft. though, so you would be better off with a single 120 in that case.
that would probbaly be good for sump diving, like as an extension to side mounting because tank size is so limited (unless you're 7 feet tall, lol)

Interspiro

[Limestone Cowboy]

Those old PST 104's I was renting were made of pure lead. I definitely need lighter tanks.

HHmmmmmm....

Figure out how many pounds of air were in those tanks.....then think about trying to swim out of a cave minus ALL of that weight after the excrement hits the rotary cooling device.

Just food for thought.

Drew

[andrebasso]

I actually thought about that, towards the end of my last dive I breathed them down to 500psi to test them - still very negative. Darn, I wish I remember exactly which model they were. I think I remember Bill Rennaker saying they were made in the 90's.

[Moonfuzzy]

Found this in the resources section, lots of info on tank specs:

http://diverlink.com/gear/tankspecifications.htm

At almost the very bottom of the page is a section on tank specs by manufatcturer. There are sized, capacities, and bouyancy info.