Adjusting my trim

[Deefstes]

OK, so it's time for a noob question again. And I have searched the forums but I get so many hits for trim adjustment with rebreathers and this or that BC but nothing general enough to answer my question.

I seem to have my buoyancy under control reasonably well now, but after I've asked my trim question I'll ask something about buoyancy control also. I'm still struggling to adjust my trim under water. My feet seem to be too heavy and I'm usually floating diagonally with my head higher than my feet.

I have a TUSA Evolution Cubic BC with integrated weight pockets on the sides and two addidtional pockets on the kidneys. I assume these are for trim adjustment but I can't seem to achieve much by using them. I dive with four kilograms of weight (that's almost 9 pounds). It means I have four 1kg weights that I can distribute around my BC. I suppose if need be I can get eight 0.5kg weights to better be able to distribute it but I'm not sure that's the sollution.

So can someone give me advice perhaps on how to adjust and practice my trim in the water? What exactly do those kidney weight pockets do? I'm reluctant to put too much weight in them as they can't be ditched easily when in an emergency.

Now for my buoyancy question. I googled around for trim tips and found a Youtube video which I'll add at the bottom of the post. I'm really impressed with this guy's trim (hoping I can achieve that soon) but I'm not sure the video really helps me much. What also impressed me is his buoyancy control. He's illutrating his trim in a swimming pool, no more than half a meter below the surface. When I'm anything closer than 3m (10ft) from the surface my buoyancy gets a little haphazard and I don't think there's any way I'd be able to hover that close to the surface. Are there extra tips or tricks for maintaining buoyancy that close to the surface?

Eagerly awaiting the wise words from the scubasages on the forum.

 

[Deefstes]

One thing I can add perhaps is that I can't really move my cyllinder any higher in my BC as it would impede my head movement then.

 

[nereas]

The diver in your e-flick is a cave diver with a backplate & wing and twin tanks.

You cannot hope to achieve the same results unless you also have a BPW.

Plain and simple, I am afraid.

 

[Deefstes]

Do mean in terms of trim or in terms of bouyancy control? Or both?

Thanks for pointing that out though, it does make me a feel a little bit less inept. But still, I need to improve my trim, even if not to the level of this guy.

 

[spectrum]

The diver in your e-flick is a cave diver with a backplate & wing and twin tanks.

You cannot hope to achieve the same results unless you also have a BPW.

Plain and simple, I am afraid.

Nonsense

 

[spectrum]

Deefstes,

Picture your body as a see-saw. Archimedes once famously remarked:"Give me a place to stand and with a lever I will move the whole world."

There are a number of things you can try to adjust your trim either by juggling items or replacing some.

You mention moving the cylinder is not an option due to head interference, fair enough. That's a helpful one for many. Choice of cylinders also can make a difference. Knowing what you now use and a bit about your build may be telling.

The trim (kidney) pockets of your BC are a tool for solving your problem. For me diving in cold water moving 6 pounds from my belt to this location did wonders. My lower body is leaner than my upper body so keeping a little weight higher on the body balances the see-saw for me.

With all of 9 pounds of weight you need to decide what needs to be ditchable. What can you swim to the surface if you had a BC bladder failure? This is one for you to figure out.

As you mention, the trim pockets are at approximately kidney height. Now apply the law of leverage to the problem. Rather than move all of your weight to your kidneys consider moving half of it to your shoulder blades. If you have room you can get an extra camband or pouch and move some weight as high as possible on the cylinder. An ankle weight or two around the crown of the tank has been known to work. I have even seen 2 of then snapped together to form a necklace but that's only really good as a test.

We have talked about shifting weights upward but your really don't have a lot to work with. What about fins? Are your's negative, neutral or positive? Something like Jets will pull your legs down. With only 9 pounds of weight I suspect you are not wearing a lot of neoprene. A more buoyant fin may be the answer. What do your have for boots? If it's a low cut lightweight style consider getting a full boot of 6 or 7 mm for buoyancy. Your feet will not get hot.

You have taken the first step in recognizing the challenge. No limit your changes on each dive so you can tell what helps and what does not. When you find it you will know it.

Diving 3 feet from the surface will be easier with good trim. We'll accept that you have your weights down right. With poor trim every kick has a vertical component and your body is creating lift like the wing of an airplane. With little vertical space this gets to be a real problem. If you were too heavy the you'd have a bubble in your BC that would vary a lot with slight depth changes. If you are under weighted then you are not equipped to dive at that depth and are fighting to stay down. You should have enough weight to make a perfectly controlled ascent to the surface with a near empty cylinder,

The diver in the video may also be in water calmer than you have been diving it.

Pete

 

[stairman]

Very good info above.Its true that a backplate/wing would help,but with some tweeking you can make any setup trim you out.Some very suttle changes can make a difference.If I dive a 3mill suit I put my wing in the top hole and have perfect trim.With a 7 mill suit Im swimming on my head and switching to the middle hole levels me back out at depth,but Im still feet up in the shallows which I dont mind.I have seen divers with weight ziptied to their upper shoulder straps.You could check that out temporarily with boltsnaped weight clipped to upper d-rings.Again be sure you can swim unditchable weights to the surface or can cut em loose in an emergency.

 

[The Kraken]

And if all else fails, get a nylon strap and place some trim pouches about the upper tank band.

Put a few pounds in there and see how it works out.

the K

 

[dkktsunami]

And if all else fails, get a nylon strap and place some trim pouches about the upper tank band.

Put a few pounds in there and see how it works out.

the K

XS Scuba pockets will accomplish this and they are designed to fit on existing cam bands. They work nicely.

 

[Buoyant1]

I'm readjusting myself this year, I purchased a Trans plate and have been having trouble getting my trim to where I like it. Seeing that the plate was about 6lbs, and I used to wear 10 in my trim pockets in my old bc, I just compensated for the weight in my pockets by adding that extra 4 lbs there. My first four dives with it I felt leg heavy, so I bought a small pouch and added it to my upper cam band and it seemed to work out a little better. I'm still not where I want it to be, but I'm getting closer.

Btw...getting a bp/w doesn't AUTOMATICALLY give you perfect trim, and you CAN have perfect trim with a jacket BC!