Odd trim problem - Make me a better diver

[DreadnoughtNH]

What happens if you completely stop finning? That's the acid test, both for buoyancy and trim. Lot's of folks have foot low trim because they are overweighted and when the stop, they sink. Stop finning and see if you're truly neutral and trimmed properly, then adjust from there.

That said, you're not far off, assuming that's your true natural trim, and you don't need to do too much.

As said earlier, hands forward will help as will bending your knees -- the latter will not only get your fins out of the dirt, it will bring them closer to your center of mass and, if your fins are heavy, it will decrease that effect because the moment arm will be smaller.

The RK3s are not what I would consider heavy fins, nor are they terrible negative, so I don't think that's the primary culprit, but bending the knees will help a lot. If the fins are 33% closer to your center of mass, that's 33% less impact they'll have on your trim.

If the posture changes aren't enough then try moving the cylinder up an inch or so. The valve and first stage are heavy and it can do wonders if you can't get trim with the posture change alone.

If none of that works, try taking 2lbs out of your integrated weights and put a 2lb weight in a trim weight pouch on the cam band.

Thanks for the input. Seems to be a consensus to put my arms further ahead; makes a lot of sense. Putting a shot of weight on the cam band and moving the tank up is not a bad idea either.

Thanks for the help! Much appreciated.

 

[DreadnoughtNH]

What happens if you completely stop finning? That's the acid test, both for buoyancy and trim. Lot's of folks have foot low trim because they are overweighted and when the stop, they sink. Stop finning and see if you're truly neutral and trimmed properly, then adjust from there.

That said, you're not far off, assuming that's your true natural trim, and you don't need to do too much.

As said earlier, hands forward will help as will bending your knees -- the latter will not only get your fins out of the dirt, it will bring them closer to your center of mass and, if your fins are heavy, it will decrease that effect because the moment arm will be smaller.

The RK3s are not what I would consider heavy fins, nor are they terrible negative, so I don't think that's the primary culprit, but bending the knees will help a lot. If the fins are 33% closer to your center of mass, that's 33% less impact they'll have on your trim.

If the posture changes aren't enough then try moving the cylinder up an inch or so. The valve and first stage are heavy and it can do wonders if you can't get trim with the posture change alone.

If none of that works, try taking 2lbs out of your integrated weights and put a 2lb weight in a trim weight pouch on the cam band.

If I stop finning, the feet inevitably swing down, but I stay neutral in the water column.

Maybe some cork anklets are in order?

 

[DreadnoughtNH]

Assuming you want to go DIR style ... then you’d probably want to refine technique rather than try and compensate with different gear. Most has been said above bur to summarize:

- Make sure you are neutral and are not finning, in the pic above your right fin tip looks like its pushing water down
- Make sure your trim is horizontal, in the pic above I’d say it’s something like 35-45 degrees off horizontal (look at the edge of your tank). If you want to check trim in the water there is an easy way: decend onto a platform or the sand, the first thing touching the bottom should be your belly. If knees or fins or thighs touch first, your trim can be better.
- Bend your knees a bit more, bringing the fins closer to your body, keep fins horizontal
- Extend arms forward, play with the position of the arms to balance your center of gravity

But ... at the same time dont get too hung up about this and dont forget to have fun

Bring the fins in and stretch the arms out. And carry a 3" Craftsman box-open end wrench in my outstretched hands. Got it.

I may be overthinking my trim. I had a blast on this trip because I felt more comfortable in the water than I ever had before.

 

[rongoodman]

Bending the knees will help and if it's not enough try to push the tank a bit higher when assembeling the gear.
Also notice that most of those DIR perfect trim situations are in a drysuit and doubles, it's a bit harder to do in a 3mm suit and single tank.

It feels easier to me, although the doubles do add a lot of mass to stabilize things.

 

[rongoodman]

Thanks for the input. Seems to be a consensus to put my arms further ahead; makes a lot of sense. Putting a shot of weight on the cam band and moving the tank up is not a bad idea either.

The consensus seems to be for you to get your feet up before doing anything else.

 

[TMHeimer]

My guess would be to switch fins. Mine are very heavy (as I noticed the 2-3 times I dropped one in shallow water and was lucky to retrieve it). My weights and tank are as far toward my head as possible and I'm still a little "down" with the fins. Not enough to warrant spending $ on lighter ones. Depends on your budget. Plus, my splits are good for cramp prevention.
There are ankle weights one can buy, but nothing that I know of as far as ankle "floats". I did use a couple of tiny floats that boats use as buffers, but too much bother and looks stupid. Then again, rarely are there people around to look at me.
I have done the arms out in front more thing which works, but gets tiresome, plus at times I'm carrying my catch bag.

 

[PfcAJ]

You dive the gear, it doesn’t dive you.

Body posture and positioning is what you need to work on. Fiddling with gear is going to frustrate you.

 

[MichaelMc]

You dive the gear, it doesn’t dive you.

Body posture and positioning is what you need to work on. Fiddling with gear is going to frustrate you.

I started playing with tiny AL40 doubles. These were my trim experiences last week and this.

I started with a 5lb. plate, 2 lb. in each of two shoulder pockets, and a 12 lb. weight belt. That worked well, but was a bit much on the shoulder straps gearing up and for in water remove/replace. (Breakwater and Monastery south)

So I moved 3 lb. to the top steel band between it and the wing/plate. That's tidier, but made me really want to turtle (Breakwater middle reef). (I had also tightened up the back of the weight belt to make it snugger.)

Should I just leave it there and work at always correcting my roll?
::leading question / sarcasm emoji::

(I did a forth dive with a really tidy one pounder on each shoulder and the weights on the belt more forward.) (Monastery south, bit of surge.)

I think I'd be cursing my gear for a while if I didn't adjust it so it worked well.

 

[NAM001]

Ok, so this may be an old question that I just cannot find the answer to.

Going through my photos from my Cayman Aggressor trip, I noticed that in every underwater photo my trim is slightly fins down. It's not dramatic, and no one ever commented on it. But unlike the classic "body parallel, finsup" trim, mine seems to be body parallel, fins down. See photo.

I'm barely using any leads at this point (6#-8#) in a full 3mm suit. However, I wonder if the culprit are my actual fins, Apex RK3s which are super heavy. I do notice that when I hover, my feet tend to drift down.

My question, am I better off removing my ditch weight modules entirely from my BC (AL Rogue) and placing those weights higher up the BC? Or swapping fins for something something lighter (my diving is almost exclusively warm water)? Or something else?

It looks like your fins are too heavy, other wise you look OK. I have 2 pair I use a set of quatros and then the jet fins for when I use a full suit or in salt water. Or you may be a little but heavy but move some weight up and see what happens. You are not perfectly horizontal . A quick check might be to raise teh tank up a bit adn look for cause and affect.

 

[Ryan Mcshane]

All about body position. Head back, arms out, clench your butt cheeks, bend your knees and widen your legs.

Experiment with using foot and arm position and see what it does to your trim.

Maybe your tank down a little to create room for your noggin. Keep the fins, rk3 are neutral in salt.