Question re: doubles

[TSandM]

There is a big gap between the two cylinders as 72's are narrow tanks while the manifolds are standard. Lots of room for a short fat lead "V" weight. Next project is to make a short but heavy tank "V" weight that can be slid up and down for adjusting trim, -losing the need for a weight belt. perfection...

A while back, somebody on TDS was selling a bunch of v-weights, and I bought a 14 pounder. I cut it in half, and I hang one half off the bottom bolt with the 72s. With that and my 12 pound weight belt, I'm just about properly weighted, and close to balanced, but not nearly as happy as in the 85s. I keep the other half of that weight down in Mexico, where it's perfect for weighting and balancing the Al80s I use down there (no weight belt).

 

[lowviz]

A while back, somebody on TDS was selling a bunch of v-weights, and I bought a 14 pounder. I cut it in half, and I hang one half off the bottom bolt with the 72s. With that and my 12 pound weight belt, I'm just about properly weighted, and close to balanced, but not nearly as happy as in the 85s. I keep the other half of that weight down in Mexico, where it's perfect for weighting and balancing the Al80s I use down there (no weight belt).

So I'm not totally off-kilter...

I now see where we differ, dead lead could be backgas.

 

[halocline]

I enjoy my double 72s, never used 85s but I've always wanted to try them. In Mexico I used a set of AL80s and was expecting to hate them, but actually I liked them better (in the water, anyhow!) than my 72s. So my next project is to find another catalina 80 (I only have one AL80) and double them up, splitting my 72s.

 

[WeekendDiver]

my guess is that it is more of a confidence issue than anyting else. i'm an instructor and dive in Dutch Springs in double 130s. complete overkill from a gas point of view of course.
Valve drills and such are nice to do when expected, and you should make sure you can reach your all your valves, and the isolator with both hands at all times, but when TSHTF you are going to get up and out anyway. That said, diving in doubles is quite different from singles because of the additional drag and mass. Different, but not worse or better.
Also, on every dive you'll accumulate nitrogen. Deco is not something to be afraid off, just something to be aware off and know your own limits. There have been times when i've been completele within any limits yet i felt screwed up and there have been times when by any measure i should have been bent like a pretzel and wasn't. Once you get it conceptually and have had some close calls. Know your body, and know what it is normal and what isn't.
rgds
WeekendDiver

 

[Mayor]

Hey, just thought that I would see what people thought about this plan.... always in the market for good advice from experienced divers!I dive locally (NYC) during the season, and I have two steel 119's which I swap between dives. Recreational diving only, mainly interested in photography and video. I dive dry, with a BP/W.I do want to eventually start technical training, but for family reasons I have decided to hold off for another season (that is, probably will start the classes a year from now in the winter, and the open water work in the spring/summer of 2013). However, I was considering doubling up the 119's (manifolded, not independent) to (a) get used to the weight and (b) get comfortable with things like valve drills, using the manifold, etc.. It would also be nice not to have to switch tanks between dives, but that's a minor point.I have tried the double 119's using travel bands, and was able to handle the weight walking to the quarry without much difficulty. I also know an instructor who will work with me this spring to make sure that I am OK with this setup before going into the ocean, and then work with me in the ocean as well in the beginning. Obviously, I'll be watching my bottom time to make sure that I don't inadvertently get into deco before I have that training....Does this sound like a good idea? Or better to just dive single for another season and then do the tech training and the doubles at the same time? Anything that I haven't thought of?Thanks!Mike

I have a few sets of alum 80's that your welcome to use. We could even do a dive togeather if you would like to meet up at DS. That's where I would start before looking in to anything else. This is from a guy who had a bunch of steel doubles when I switched over.

 

[Mayor]

my guess is that it is more of a confidence issue than anyting else. i'm an instructor and dive in Dutch Springs in double 130s. complete overkill from a gas point of view of course.Valve drills and such are nice to do when expected, and you should make sure you can reach your all your valves, and the isolator with both hands at all times, but when TSHTF you are going to get up and out anyway. That said, diving in doubles is quite different from singles because of the additional drag and mass. Different, but not worse or better.Also, on every dive you'll accumulate nitrogen. Deco is not something to be afraid off, just something to be aware off and know your own limits. There have been times when i've been completele within any limits yet i felt screwed up and there have been times when by any measure i should have been bent like a pretzel and wasn't. Once you get it conceptually and have had some close calls. Know your body, and know what it is normal and what isn't.rgdsWeekendDiver

Are you diving steel 130 doubles in a wet suit? That's a lot of weight to swim up.

 

[lowviz]

Nice offer Mayor,

OK, I have 72's, 100's, and 119's. Could be fun. Maybe we should start a "you fill'em, you dive'm" weekend...

I like it.

 

[Mayor]

Nice offer Mayor,OK, I have 72's, 100's, and 119's. Could be fun. Maybe we should start a "you fill'em, you dive'm" weekend...I like it.

Anytime! If I'm not using them they still like to get wet.

 

[lowviz]

Anytime! If I'm not using them they still like to get wet.

Sweet.

 

[SeaCobra]

I had a set of e8-119's doubled up and them them to be awfully heavy and past the point of diminishing returns for me. The extra gas was consumed by the weight and drag of these tanks. I have since broken them down and put h valves on them, they make great tanks for my recreational ocean diving. I have gone back to my faber 98's for the deep stuff, I have twin 75's for mid-range and accumulated some twin al 80's as well.

I am up at Dutch quite a bit, let me know if I can help. Will be at the Baltimore scuba show this saturday and of course at beneath the Sea.

BTW - loved the magic bus video!