How many tanks ?

[PfcAJ]

"When the gas is done, the deco is done!"

 

[Octopusprime]

Deco bottles are a bit more personal than you make out. My buddy uses a Faber 10l for first deco, as does another shorter diver I know.

Back to the OP. If you are seriously considering two twinsets maybe you should have a think about a rebreather. Maybe you have the space, a huge truck etc but for me a weekend away that involved two twinsets per diver plus enough deco gas would mean one car per diver and make the logistics much harder.

one other thing though... I'm planning on teaching open water with my brother in law. Because of this I will need a bunch of al63 or al80s anyway. If we go diving for a weekend anyway we are allready brining 6 tanks, when we teach we will need at least 12 tanks. We have big SUV and going to get a trailer.

---------- Post added February 14th, 2015 at 07:27 PM ----------

If doing two deco cylinder dives by the book there are some non obvious (at least to me) implications for cylinder choice. Lost gas scenarios mean you need to be able to deco out on whichever cylinder you have left. This means that a plan calling for only maybe 400l of week deco gas might require lots more if you loose the rich gas.

Yes the plan is gear for 2 deco dives in a day (no oppertunity to refil on boat) 100-140ft NO trimix (yet) most likely nitrox and O2 deco depending on dive profile. Want to plan for failure for me or buddy to have enough gas to ascend and deco stop.

 

[Superlyte27]

If doing two deco cylinder dives by the book there are some non obvious (at least to me) implications for cylinder choice. Lost gas scenarios mean you need to be able to deco out on whichever cylinder you have left. This means that a plan calling for only maybe 400l of week deco gas might require lots more if you loose the rich gas.

Not really a big deal. An AL80 will last me a LONNNNNNNGGGGGG time At 20' something in the neighborhood of 200 minutes. I only carry deco bottles incase the rebreather dies. And on my next big dive there will be a rebreather sitting at 30' in case my rebreather dies. I REALLY don't want to do 4+ hours on OC deco'ing.

It's just a lot easier to carry aluminum than steel when you're talking about 5-8 bottles on you for bailout.

---------- Post added February 14th, 2015 at 09:55 PM ----------

one other thing though... I'm planning on teaching open water with my brother in law. Because of this I will need a bunch of al63 or al80s anyway. If we go diving for a weekend anyway we are allready brining 6 tanks, when we teach we will need at least 12 tanks. We have big SUV and going to get a trailer.

---------- Post added February 14th, 2015 at 07:27 PM ----------



Yes the plan is gear for 2 deco dives in a day (no oppertunity to refil on boat) 100-140ft NO trimix (yet) most likely nitrox and O2 deco depending on dive profile. Want to plan for failure for me or buddy to have enough gas to ascend and deco stop.

Where are you at in the process. Whats your real dive count now. How many have been technical dives. How long have you been diving. What is your current cert level. How many dives have you made in doubles?

You got a lot of posts recently, and you seem to be putting the cart way before the horse.

 

[KevinNM]

"When the gas is done, the deco is done!"

One way or another....

 

[KenGordon]

one other thing though... I'm planning on teaching open water with my brother in law. Because of this I will need a bunch of al63 or al80s anyway. If we go diving for a weekend anyway we are allready brining 6 tanks, when we teach we will need at least 12 tanks. We have big SUV and going to get a trailer.

---------- Post added February 14th, 2015 at 07:27 PM ----------



Yes the plan is gear for 2 deco dives in a day (no oppertunity to refil on boat) 100-140ft NO trimix (yet) most likely nitrox and O2 deco depending on dive profile. Want to plan for failure for me or buddy to have enough gas to ascend and deco stop.

I don't do more than one dive a day which requires more than one deco cylinder. If doing your two 30m to 40m dives I take one twinset and top it up on the boat from a 300 bar 12, so I start the second dive with maybe 150 to 170bar. Here someone turning up at a boat with two twinsets would raise eyebrows.

Going back to your first post. Keep the Ali 80s as deco cylinders and get a twinset as back gas. The material and construction of the twinset will depend on you suit choice and body type. I dive twin 'Euro' cylinders. These are a bit longer and heavier than Fabers. I would never dive a single Euro, only single Fabers. I use a drysuit and so heavy is good. If diving a 3mm wetsuit then maybe aluminium would be better.

In diving it is important to try stuff out. This is best done before spending money. What works for you may not be what worked perfectly for someone else.

 

[tbone1004]

Chris, if you're teaching instead of a boat load of 63's and 80's, scrounge as many LP72's as you can find. Will save you a lot of money over aluminum and having to buy a bunch to lead to fill weight belts with...

 

[victorzamora]

"When the gas is done, the deco is done!"

If that were true, everybody would be carrying around AL6s.

 

[Tracy]

If that were true, everybody would be carrying around AL6s.

Think it through, what he said is correct.

 

[Octopusprime]

Spent the afternoon at DRIS. Mike and Chris are Awsome. I think 2 HP100's are next.

 

[decompression]

Good choice. [emoji3]


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