What is your preference on deco bottles?

[zaberman1]

You know, everyone says that they prefer the Luxfer 40s, so that's what I got. But I want to know why.

If Luxfer 40s or 80s get down to about 1,500 PSI they get really light. If you figure that with a transfill whip I can get my O2 bottle to only 2,000 PSI, it doesn't take long for the cylinder to get light.

And once it's light, it's really buoyant, floats bottom up, and it's a pain in the ass to reach back, push the bottles out of the way and unclip the SPG.

It would seem to me, in my limited experience, that a bit heavier bottle would be more easily managed. Is it strictly the weight of the bottle at the start of the dive? Why do people like the Luxfer 40s and 80s?

Comments please.

Clamping a weight at the end is a good idea but you could also go for the neutral al 40's. I'm thinking about trying a steel 40, its not that heavy and heard it does the trick...

 

[Rick Inman]

You know, everyone says that they prefer the Luxfer 40s, so that's what I got. But I want to know why.

If Luxfer 40s or 80s get down to about 1,500 PSI they get really light. If you figure that with a transfill whip I can get my O2 bottle to only 2,000 PSI, it doesn't take long for the cylinder to get light.

And once it's light, it's really buoyant, floats bottom up, and it's a pain in the ass to reach back, push the bottles out of the way and unclip the SPG.

It would seem to me, in my limited experience, that a bit heavier bottle would be more easily managed. Is it strictly the weight of the bottle at the start of the dive? Why do people like the Luxfer 40s and 80s?

Comments please.

For me, the lighter bottom end can be a good thing. It rides well under my arm, especially if I'm using multipal bottles where it would be on the top. Also, if I want to put it on a leash on my butt after I've used it, it floats up nicely behind me, rather than hanging down between my legs.

 

[rjack321]

You know, everyone says that they prefer the Luxfer 40s, so that's what I got. But I want to know why.

If Luxfer 40s or 80s get down to about 1,500 PSI they get really light. If you figure that with a transfill whip I can get my O2 bottle to only 2,000 PSI, it doesn't take long for the cylinder to get light.

And once it's light, it's really buoyant, floats bottom up, and it's a pain in the ass to reach back, push the bottles out of the way and unclip the SPG.

It would seem to me, in my limited experience, that a bit heavier bottle would be more easily managed. Is it strictly the weight of the bottle at the start of the dive? Why do people like the Luxfer 40s and 80s?

Comments please.

With a reg on, the 40s are essentially neutral. MAYBE +1 lb if your deco reg is smaller and or lighter. The 30s are actually negative with a reg on.

A steel 45 is definitely negative. So it will always hangs low on the clips instead of riding behind your arm (like an AL80 full of nitrox in freshwater). If a steel 45 got tangled and had to be cut free; you would now be too light to hold your deco stops.

I use mostly al40s but sometimes one or more al80s.

 

[Colliam7]

I would like to know what size deco bottles everyone feels trims out better. I have heard both 40cf and 30 cf are used. .... as long as either would be sufficiant, which do you preffer...

You know, everyone says that they prefer the Luxfer 40s, so that's what I got. But I want to know why. .... And once it's light, it's really buoyant, floats bottom up, and it's a pain in the ass to reach back, push the bottles out of the way and unclip the SPG. .... Is it strictly the weight of the bottle at the start of the dive? Why do people like the Luxfer 40s and 80s?

I may be going against the grain (you can never have too much gas, so why not go with the bigger bottle), but I prefer to take the smallest bottles that will allow me to safely dive my plan, with reserves. I dive 80s, 40s, and 30s. I generally prefer to dive two deco gases (usually 50% and 100%), and I prefer to clip both bottles on the same side (left). In the water, I don't really notice the bottles - size, weight or trim - and I can't say I really notice differences in trim between the sizes, at the beginning or end of a dive. Maybe I am just oblivious. I haven't noticed a problem getting to my SPG, even with an 80 and a 40 clipped on the left. On land / boat, I DO notice the size and weight of my deco bottles, and I prefer to minimize that. So, if I can run a dive with a 40 and a 30, I will, simply because that is a smaller mass on my left side. As to why I use a particular size: I dive: A) an 80 because 1) my first (purchased) tank was an AL80, after which I bought some HP 120s for single tank diving so the AL80 saw increasingly infrequent use, and 2) when I moved to doubles / deco diving I had it available so I turned it into a deco bottle; B) an AL40 because I bought it long before I did tec training (but after I decided that was something I was going to do), because I heard that was a frequently used deco bottle size, so I used it as a pony bottle for several years, to get used to carrying a clipped bottle; C) an AL30 because they (I have 2) came with some used double AL80s that I bought several years ago. I wish they were 40s, but 'the price was right'. All my aluminums are Luxfers because that was what my LDS had (80 and 40) and what the 30s (and double 80s) happened to be. So, there was no master plan in the selection of size or manufacturer, but I find they all work. In an ideal world I would only carry two AL40s - they usually have enough gas for the types of deco dives I do, and they are a good size for clipping 2 to a side.

 

[Colliam7]

Also, I am intrigued by folks who dive steels as deco bottles. That seems like it would really add to the total weight but the comments I see on SB suggest that steels may work well as deco bottles.