Is a 40cuft indefinitely useful?

[stuartv]

Jesus which one do I use for an /dp and why doesnt the class all use the same thing ?.. thread evolving.

Your AN/DP instructor will almost certainly tell you which one to use. My TDI AN/DP class was all told to buy Multi Deco and we used that for the whole class.

I wish I knew more of the dive planning that happens in an/dp.

Get Steve Lewis' book, The Six Skills. That will tell you a LOT.

https://www.amazon.com/Six-Skills-Other-Discussions-Solutions/dp/098122802X/

 

[211ratsbud]

I wish that were in the "play store" damnit no need for a hardcopy

 

[KenGordon]

I think the exchange above illustrates that this is not a totally simple cut and dried subject. You are going to pay money to some character to teach you this. If you think you know it all beforehand you will get bored and miss the little key points you did not know.

If you must bring a cylinder then take an 80 rather than buying a 40. The rigging kit is the same except for the size of jubilee clip.

Doesn't intro to tech cover planning and tables? AN/DP planning is that but more so and with multiple gases. The multiple gas part is a bit of a departure regarding how you plan for failures since now not all gas is the same.

 

[Remy B.]

a 40cf bottle is probably the most versatile bottle to grow in Tech Diving, it is enough for AN/DP, and as you advance you can used for a 50% Deco like others mention, while your shallow can be a 7L Alu or a AL80

I have a 40Cf and if I have a chance I want to get my hands on a 7L Alu tank (200bar)

Regarding 300Bar bottles, remember that is alright for some Nitrox, but 300bar with 50% or higher begins to be dangerous, I know of some incidents with people here in Nederland because of that, one I met personally and he and his boat are lucky to be alive.

here is the EU and UK 300bar bottles are very common, I have two 7L carbons that I use every weekend nothing beats that regarding weight vs capacity. but Steel bottles for 300bar are very heavy, 8.5L steel 300bar are very common here used as doubles.

 

[victorzamora]

7Lx200bar is ~50Cf. I'm not sure I'd worry about that intermediate step and I'd jump straight from AL40 to AL80. If my AL40 is marginal, I doubt an AL50 would make me feel any better.

Those 7L Alu tanks also aren't available on this side of the pond as far as I'm aware.

 

[Remy B.]

Is a question of growing with your diving, using a 40cf = 5.6L for 50% and a 7L for 80% get you a step forward, then when you are more up to longer deco's you can use de 7L for 50% and buy a 80cf for 80% and use the 40cf as backup or a 25/35 mix.