Odd trim problem - Make me a better diver

[DreadnoughtNH]

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?

 

[tbone1004]

heavy fins don't help
knees aren't bend all the way
there is a reason all of the "DIR Diver" pictures you see have their hands out in front of them. It helps greatly at countering heavy feet.

 

[runsongas]

looks like the rk3 fins, which shouldn't be terribly heavy.

 

[rongoodman]

Get your feet up, then decide whether you need to move some weight forward. It doesn't look like you're dropping your knees.

 

[jgttrey]

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.

 

[guruboy]

Are you making a conscious effort to maintain body position?

 

[tursiops]

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.

Both these small changes can do wonders. But knees bent and feet up is the #1 think to do.

 

[Vicko]

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.

 

[JackD342]

RK3 fins may be a little heavy to pack, but they are only slightly negative in water. Would probably float without the spring strap. So, I don't think it is the fins.

If that photo is actually level, it looks like your knees are about 18" lower than your shoulders, and it is probably your trim that needs work.

Having said that, I think it is not unheard of to have difficulty lifting your head enough to look straight forward when in perfect horizontal trim. So you may already be at your optimal balance for personal comfort.

 

[1atm]

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