High Pressure Fibre Tanks for shore diving???

[BRT]

Still you can't compare a Worthington carbon 300 tank to anything in the market, they out perform anything out there so far I know.

When Worthington quit making hot dip scuba cylinders I wondered if they thought there was something far superior out there. They won't be for me but I think in 20 years they may be the way to go.

 

[Storker]

Where do you get a 400BAR regulator or DIN valve?

That's a very good question, which I was hoping that you could answer

Still you can't compare a Worthington carbon 300 tank to anything in the market, they out perform anything out there so far I know.

Depends on what you need and/or want. For my needs and my diving, Faber steel 300s outperform anything else I've used, and for my needs, they probably perform better than your tanks would. I like my tanks to be quite negative since that shaves weight off my belt, and in my config, 10L 300 bar tanks make the best compromise between total rig weight and gas capacity. A 7L would give me 30% less gas than I'm carrying today, and even on air, I'm already gas limited just as often as I'm NDL limited.

"Performance" is a relative term and its magnitude depends on how the specific user prioritizes properties.

 

[Remy B.]

I dive with 2 X 7L 300 carbons, weights half and is almost 2/3 less bulk than 2 X Al-80, so it meets my priorities, easier to store anywhere as well, that means I'm always redundant, and carry more gas than a single 12L X 300 Carbon.

 

[Storker]

I dive with 2 X 7L 300 carbons

And I have clubmates who dive with D7x300 steels and still carry (more than) enough ditchable weight on their belt. If they were to switch to carbon tanks, they'd just have to add the weight difference to their belt. What advantage would then carbon tanks give?

 

[Remy B.]

not my fault they don't know how to weight them self out properly, the difference between the two are not that big.

I dive sidemount, I prefer small and light high capacity bottles outside the water, in the water all cancels out if weighted properly

 

[BRT]

And I have clubmates who dive with D7x300 steels and still carry (more than) enough ditchable weight on their belt. If they were to switch to carbon tanks, they'd just have to add the weight difference to their belt. What advantage would then carbon tanks give?

One advantage of lighter tanks is you only need to have one set of weights but you may need to load several tanks.

 

[Storker]

not my fault they don't know how to weight them self out properly, the difference between the two are not that big.

Huh? I didn't say that they're overweighted. Let me rephrase that in simpler terms for you:
When they are
correctly weighted
for their exposure protection
they carry a fair bit
of weight on their belts
i.e. ditchable weight.

Lighter tanks
are of no use to them
since the weight difference
would have to be compensated
by more on their belt.

I dive sidemount, I prefer small and light high capacity bottles outside the water, in the water all cancels out if weighted properly

Well, backmount is still the normal type of rig. Taking an example from specialized sidemount gear and claiming it's better than the stuff people prefer for backmount - for good reasons - doesn't seem like the pinnacle of logic to me.

 

[Patoux01]

And I have clubmates who dive with D7x300 steels and still carry (more than) enough ditchable weight on their belt. If they were to switch to carbon tanks, they'd just have to add the weight difference to their belt. What advantage would then carbon tanks give?

A reduction in inertia and torque on the back when carrying the tanks, for instance.
A more neutral tank also allows for better control underwater (because if it's negative, it'll tend to have the diver belly-up if swimming on the side, and belly-down if it's positive).

I'm not sure for carbondives, but for ARI (SCBA tanks, but they're quite in use in cave diving in France), people wrap some lead around them to make them less buoyant, while still being much smaller and lighter than equivalent non-fiber tanks.
I'd try carbondives if they didn't cost over half my rig per tank...

 

[guyharrisonphoto]

Remy, what is the buoyancy (not weight) of the 12L carbondive full and empty? I have not been able to find that information anywhere.

 

[geoff w]

...I moved back to southern California, and while the funds are tight I can't afford to do all my diving off a boat.

I was looking around at tanks and noticed that fire fighters use a fibre wrapped tanks filled to 4500 psi (300bar). Some online specs indicate these tanks are much lighter than our Al or steel tanks we prefer for diving. Would these be a reasonable option? The main purpose for wanting a lighter higher pressure tank, is from a SI joint injury thats never been fully resolved, that makes lugging tanks for shore diving more miserable than it already is...

I'm a regular So Cal beach diver, and frequently walk/hike trails, across sand, around rocks, etc. to get to dive entries / exits. A lot of my regular buddies are more on the mature than younger age scale, but we often have 20 and 30 year old join us, so big age and fitness range, along with plenty of other-sport injuries over the years

I typically dive with a HP80, most of my buddies dive HP100s. From a weighting standpoint and getting out through moderate surf, a HP80 is hard to beat. It's like having a bowling ball on your back - very negatively buoyant and all the mass is centered on your back, so easy to turn / rotate if a wave is coming toward you. A HP80 is almost 2 lbs more negative (i.e., you need 2 lbs less lead) than a HP 100, and about 6 lbs more negative than an Al80. Downsides are cost compared to an Al80 and difficulty getting a really good fill (even more of an issue than a HP100 because it gets so hot during a fill and cools off a lot). High pressure steel tanks also appear to be more susceptible to rust than Al80s or low pressure steel tanks. With a 7 mm full suit, hooded vest underneath, gloves, booties and steel backplate, I typically dive with 2 lbs of lead. The other nice thing about a HP80 is it fits into a plastic tub pretty easily, so you keep it from dripping salt or sand inside your car

Another good (and economical) tank option for beach diving is an old steel 72. They're about the same buoyancy as a HP100 as far as weighting, relatively inexpensive, readily available, and it's easy to get good fills (and with basic care will last almost forever). They're smaller diameter than an Al80, HP80 or HP100, so do well getting out through moderate surf too. Low pressure 85s are another good choice, about the same form factor as an Al80 or HP100 (and about the same buoyancy as a HP100), but pricier.