What size doubles?

[b1gcountry]

I'm in the same boat as the OP, although I might be a tad farther away from my first purchase. Living in the middle of country, though, I'll be diving mostly freshwater. Looking back through my dive logs, I've only worn 12 lbs with a single AL80 plus AL BP; and 6lbs with a single HP100 plus AL BP diving freshwater. From what I've read about double AL80s, they weight out about the same as a single AL80 (when empty, the extra weight from the manifold, and extra first stage offset the buoyancy of the tanks). So I would guess I would still need about 12 lbs with the double AL80s.

With Double Steels, I'm already only wearing 6lbs. If I doubled the tanks up, I would probably be close to neutral with no extra balast. Wearing anything other than the drysuit, I would probably be heavy.

One of the reasons I'm looking at doubles is to check out some of the caves/mines in the area. The most interesting one I've found is only 70' deep or so, so huge tanks would not be necessary in my mind. The other interest would be in Great Lakes wrecks, and 160cf should be fine for most of that stuff as well, and would get me two dives at most recreational depths.

I've got two HP100s right now. Doubling them up is not an option (wife dives them). I was considering getting some HP130s, or just going ahead and setting up some doubles with AL80s.

 

[rookers]

My first set were X7-120s, they trim really well for me (6'3"), but of course its sometimes hard to get them filled to rated. I also own LP108s which don't trim quite as well, but filled to 3k give a lot of gas. I like them both, and have dove numerous other sets, none of which I really found objectionable, other than some LP80s and only because I had to wear some lead with them and a drysuit.

 

[xiSkiGuy]

SkiGuy-
I thought the X8-130s were the same height as the X7-100s? with just about the same buoyancy empty?

No. The X8-130s are at least an inch and 1/2 taller, if not 2". Seen side by side, the difference is obvious. Empty buoyancy is probably similar, but I've never known someone who has used both (doubles) to describe them overall as "similar".

PS, I'm 6'6" and dive the X7-100. Diving dry, I trim fine. Diving wet, it depends what depth I'm at.

Are you diving a single or doubles? I can make a HP80 trim out fine with singles. Doubles are a bit tougher.

 

[b1gcountry]

I'm diving singles only. Haven't doubled anything up yet.

I own two X7-100s, and I borrowed NWGratefulDiver's X8-130 while I was diving up in the PS area last month. My feet dropped a little with the 130 whenever I was below 40', and they were floaty at the safety stop. I was wearing a lot of neoprene though.

I never had the two side by side, so I couldn't tell relative height. They felt about the same as my 100s, but there were a lot of other things different about that dive that might have just been more obvious. (first time with a can light, no stage bottle, wearing more neoprene than usual, etc.)

Theoretically, though, if I were to double up some large steels, being 6'6" tall, it sounds like you would expect the taller tanks to trim out better. The X8-130, or even the X7-120, instead of the X7-100?

Tom

 

[xiSkiGuy]

Theoretically, though, if I were to double up some large steels, being 6'6" tall, it sounds like you would expect the taller tanks to trim out better. The X8-130, or even the X7-120, instead of the X7-100?

Yes. Theoretically, the X7-120s would work really well for you.