Getting Horizontal Trim

[befee]

I wasn't quite sure where to put this, so I figured adv. scuba would garner the right focus and publicity.

After looking at photos from last summer I noticed my trim isn't where I want it to be for single tank warm water diving.
Wearing: 3mm full wetsuit and 6lb SS backplate, al80, I am neutrally buoyant at the end of the dive.
Problem: It seems that I am foot-heavy (legs sagging)
Additional Problem: I recently moved to Hollis F1's which are more negative than the fins I was using previously.

I was thinking of adding a few pounds onto the cam band to put weight above my center of gravity, but wasn't sure if this was a bad idea. My only aversion to it is that I would start the dive even more negative and finish the dive negative. I doubt I would have a problem swimming up the additional weight so balanced rig seems okay.

I thought I saw TSandM post somewhere once about lowering the tank but I don't recall the reason or effects.

Ideas? Thought?

PS. I do have my arms extended, as far as pictures show my shoulders to knees are inline, and the tank is already raised as high as I can reasonably reach the valve.

 

[dpaustex]

You want to shift your weight forward. That would mean putting your BC lower on your tank. This could be a problem with your head hitting your first stage, though. I have legs that don't float well, either, but when I am taking photos, I am in a "foot up" position (bend your knees, but keep your legs straight at the hip).

I would not recommend adding weight, simply because you'll be overweighted. I wouldn't put too much stock in the photos. Have someone swim alongside you. If you're swimming in a "fins down" position, that would be troublesome, as you're presenting a larger cross-section in the water, and burning air/effort to push that inefficient cross-section through the water. I've heard of ankle weights - but for the opposite problem. Maybe you could invent ankle floaties......

Keep playing with it. It's good that you're cognizant of the issue, and wanting to fix it. I'll check with my fellow instructors and see if any of them have come across this one before.

 

[NorCalDM]

I would agree with dpaustex don't add any weight just shift what you have. If all your weight is on a weight belt that could push your hips down, move some of this weight closer to your shoulders. I wear 2mm neoprene socks under my dive booties and it makes my feet more floaty! If you search this site there was another thread receintly about the same issue.

 

[rongoodman]

You're right--the F1s are fairly heavy. Try a lighter fin, such as the OMS Slipstream or Dive Rite EXP. You can always use the F1s for local diving in a drysuit with doubles! (They'll probably sell pretty quickly in the Classified section here, if it comes to that.)

 

[befee]

I'm not currently wearing any additional weight other than the backplate. I might try to get thin liners for my boots to add some positive buoyancy for my feet.

Ron, I'm keeping the F1's.

 

[Superlyte27]

Moving an AL80 tank will not do much. Those fins are pretty heavy. I wear them, switching to a drysuit fixed them from being too heavy. A steel tank would solve the issue. Moving the tank even 1/2" would make a difference. Or change to lighter fins. Which I was not willing to do.

 

[Peter_C]

Bring the fins closer to your butt when you stop. It is amazing how much a difference your legs/fins can make in your trim.

Might be cheaper than replacing the fins to buy a used aluminum plate, then add some weight back in at the top of the tank with something like an ankle weight.

Which kick do you use? Frog or flutter?

 

[befee]

Moving an AL80 tank will not do much. Those fins are pretty heavy. I wear them, switching to a drysuit fixed them from being too heavy. A steel tank would solve the issue. Moving the tank even 1/2" would make a difference. Or change to lighter fins. Which I was not willing to do.

This is during travel, so changing tanks in unlikely.

Bring the fins closer to your butt when you stop. It is amazing how much a difference your legs/fins can make in your trim.

Might be cheaper than replacing the fins to buy a used aluminum plate, then add some weight back in at the top of the tank with something like an ankle weight.

Which kick do you use? Frog or flutter?

I would rather not change fins and I'm a frog kicker.

Truthfully though, how bad would 1 or 2 pounds be if it comes to it? If I can swim it up with full tanks and diving at recreational depths? I'll still have my liftbag in my backplate if absolutely necessary.

 

[Superlyte27]

I had the same issue with the same fins just a few weeks ago with my rebreather. No amount of weight I added to my shoulders would fix my leg issue. I first tried changing fins, but I loved the F1's. I finally bought a drysuit. A bit extreme, but problem solved.

 

[befee]

I had the same issue with the same fins just a few weeks ago with my rebreather. No amount of weight I added to my shoulders would fix my leg issue. I first tried changing fins, but I loved the F1's. I finally bought a drysuit. A bit extreme, but problem solved.

I got the fins specifically for my drysuit diving (most of my diving). Maybe I'll pack it with me.