If the HP80s are filled properly, there’s not a problem unless they’re too small for your planned dives.
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Woefully inadequate HP80'S
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seeker242
Contributor
Bob DBF
Contributor
HP tanks 3500# and 3445# are covered by a special DOT exemption and do no have a + rating for the tank.
3AA tanks, which are lower pressure have a + rating until it is not able to certify for the plus at hydro. Unfortunately some shops won't look up the specs or test for the + rating. The new tanks have the REE number stamped on it that is needed for the + certification stamped on the tank, won't help if the hydro shop refuses to give the +, so know who you are dealing with when you send a tank in for hydro.
Bob
Lobzilla
Contributor
+1
If you have 3AA tanks with a "+" next to the born date, insist on keeping that rating. It requires additional testing equipment at the hydro facility to measure the minimum wall thickness. If they give you excuses that the "+" rating needs to have been issued at every hydro (which is BS) or other excuses why they supposedly can't do it, find another facility. (If the tanks fail the "+" test, that's another story of course)
Lobzilla
Contributor
I switched to doubles a few dives after AOW and have since become a huge fan of double tanks for Recreational+ diving.
With "Recreational+" I mean anything between a tropical reef tourist bimble and technical diving. Examples are cold water diving, no-penetration wreck diving, lobstering, scallop dives, in short anything where extra gas and redundancy is a strong asset.
What most people do not realize is that doubles not only give you redundancy for your gas supply but also allow you to take the reserve from the first dive into the second one, instead of leaving it on the boat/shore. With doubles you will always have more gas at any point during two consecutive dives than a two single-tank diver with comparable tanks and sac rate.
Also, weight is not as big of an issue as some people think. I have a set of baby doubles that weigh a mere 6 lbs more than a single tank of comparable volume (100 cuft). To be fair, on the other end of the scale is a set of doubles holding about 300 cuft and weighing about 100 lbs - the most I dare to waddle to the water for more than a few feet.
There is a little bit of transition training involved but you will quickly realize that doubles are actually nicer to dive. They lay flat on your back, wing buoyancy is further out to the sides and you get rid of the single tank wobble around the roll axis. I still can dive single tanks just as well but it is more work, ironically.
Cost-wise, it takes another $250-300 for manifold and bands to convert two (suitable) single tanks to doubles. Plus the one-time expense for another first stage, another wing (or your first BP/W), and a few cheap hoses. From my experience, that was worth every penny.
With "Recreational+" I mean anything between a tropical reef tourist bimble and technical diving. Examples are cold water diving, no-penetration wreck diving, lobstering, scallop dives, in short anything where extra gas and redundancy is a strong asset.
What most people do not realize is that doubles not only give you redundancy for your gas supply but also allow you to take the reserve from the first dive into the second one, instead of leaving it on the boat/shore. With doubles you will always have more gas at any point during two consecutive dives than a two single-tank diver with comparable tanks and sac rate.
Also, weight is not as big of an issue as some people think. I have a set of baby doubles that weigh a mere 6 lbs more than a single tank of comparable volume (100 cuft). To be fair, on the other end of the scale is a set of doubles holding about 300 cuft and weighing about 100 lbs - the most I dare to waddle to the water for more than a few feet.
There is a little bit of transition training involved but you will quickly realize that doubles are actually nicer to dive. They lay flat on your back, wing buoyancy is further out to the sides and you get rid of the single tank wobble around the roll axis. I still can dive single tanks just as well but it is more work, ironically.
Cost-wise, it takes another $250-300 for manifold and bands to convert two (suitable) single tanks to doubles. Plus the one-time expense for another first stage, another wing (or your first BP/W), and a few cheap hoses. From my experience, that was worth every penny.
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Ive been seriously considering going to a double set for more gas and redundancy on deeper non-penetration wreck dives, however these dives require a significant boat ride to the site.Have you dived doubles from a boat? Is it practical or logisitically doable ? Do i need a seperate certification to go doubles? What training is involved and who will do the training?
You don’t need a cert class. One doesn’t exist just for doubles, unlike SM. A mentor is definitely helpful. Doubles are easier from a boat than SM.
There are certifications for doubles. There are intro to tech classes and intro to doubles classes. They are not mandatory at all but can be helpful if you don't have a mentor to help you get into diving doubles.
CuzzA
Wetwork for Hire
Hmm, I don't know, Akimbo. I own 8x LP112's and have found they can pretty much handle everything below the surface. Single, doubled, sidemount. They trim out great, have great buoyancy characteristics, and as long as you have a shop that is competent and understands there is no more added risk to properly filling low pressure tanks, then they might just be the perfect tank... in my very biased opinion.
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