What do you mean by "Trim"?

wreckchick · Jul 9, 2003

Trim is a word that almost everyone on the board uses but depending on who's saying it and in what context it seems to mean different things.

My personal definition of trim is the attitude that my body assumes in the water when I cease all motion and I'm holding a given body position. This means that "trim" is not affected by anything that I do while I'm diving but has everything to do with how my rig is balanced prior to the dive.

Is that how you use the term or do you use it differently and what's your definition?

Rachel

MXGratefulDiver · Jul 9, 2003

Yep, that's pretty much how I understand it ... although I tend to view it as how you've distributed your gear throughout your entire body, not just your rig.

... Bob (Grateful Diver)

Zagnut · Jul 9, 2003

..except that you don't have to be motionless. It's about how you are situated (you called it attitude)while either still or while swimming.

I guess I think of trimming a boat motor. Adjusting the trim on a boat (bass boat with outboard motor, in my case) changes the angle and depth the rotor sits in the water and it affects the plane of the boat (among other things). You can trim a boat motor while the boat is moving.

So I guess I would say it's adjusting your gear config and/or technique to get desired attitude in the water whether moving or still.

JohnF · Jul 9, 2003

FWIW I've seen the question asked a number of times "What's the difference between trim and balance?". The most common answer is that the terms are interchangeable.

But as I've followed discussions in different forums I've come to think of trim as the way a diver distributes weight and buoyancy gear about their body, and how it affects their body's attitude and control in the water. Balance, otoh, is the way a diver matches their weighting to their other gear. For instance, we hear divers refer to a balanced rig. I take that to mean a rig with no excess lead involved, only enuf to allow the diver to hold a stop at any depth with any amount of air in the tank(s) without undue effort.

YMMV

JohnF

wreckchick · Jul 9, 2003

John, that makes total sense and my use of the word "balanced" was probably improper. The idea I was trying to convey is that trimming is a process that's undertaken prior to the dive. You can throw previously good trim out of whack by changing fins even if you stay in balance.

R

Walter · Jul 9, 2003

Trim is your attitude in the water. How you distribute your weights can affect it, but the term is not dependent on equipment configuration. I can easily assume any attitude in the water I desire.

I'm amazed that DIR folks are so into training and against being equipment dependent, yet they want their trim entirely controlled by equipment (weight placement). Seems like a contradiction to me.

Charlie99 · Jul 9, 2003

Walter once bubbled...
Trim is your attitude in the water. How you distribute your weights can affect it, but the term is not dependent on equipment configuration. I can easily assume any attitude in the water I desire.

The real trick is how long will you stay in that attitude when you stop moving. That's where moving weight and equipment around makes a difference.

The other difference is whether you can pick ANY orientation. It is easy to get a very stable, horizontal trim by putting a bunch of weight on your belly side and having a wing above you (aka dirigible config). It's trickier to get center of upward buoyancy force and center of negative buoyant forces to coincide. Then you can roll, pitch, or yaw as desired and stay there.

JohnF · Jul 9, 2003

Walter once bubbled...
Trim is your attitude in the water. How you distribute your weights can affect it, but the term is not dependent on equipment configuration. I can easily assume any attitude in the water I desire.

I'm amazed that DIR folks are so into training and against being equipment dependent, yet they want their trim entirely controlled by equipment (weight placement). Seems like a contradiction to me.

I'd agree with that definition of trim as long as you're not saying that good trim is possible regardless of gear config. Obviously it would be pretty tough for even the most skilled of divers to maintain good trim with 24# of lead attached to his feet. I'm sure you'd agree that your ability to assume any attitude in the water column is dependent on having your gear sensibly configured.

What does our definition of trim have to do with DIR? I know many other non-DIR, even anti-DIR, divers whose trim is about as close to perfect as is humanly possible.

JohnF

Walter · Jul 9, 2003

I am saying good trim is possible regardless of any reasonable gear configuration. I would never put any lead on my feet.

Trim should be important to any diver, DIR or not. It seems, to me, there is a contradiction in the DIR approach to trim from that of most of their approaches to other topics. Merely an observation on my part.

JohnF · Jul 9, 2003

Walter once bubbled...
I am saying good trim is possible regardless of any reasonable gear configuration. I would never put any lead on my feet.

Trim should be important to any diver, DIR or not. It seems, to me, there is a contradiction in the DIR approach to trim from that of most of their approaches to other topics. Merely an observation on my part.

Good. So we are on the same page trimwise, and don't worry, I'm not a DIR acolyte, but I'm curious, so at the risk of derailing this thread, how is the DIR approach to achieving good trim a contradiction. I've found the logic behind pretty well all the DIR protocols to be basically unassailable, albeit a tad restrictive and/or overdone in a very few instances.

I think since you brought DIR into the thread, this point is still germane.

John Francis

What do you mean by "Trim"?

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