Problem with trim using doubles

[ckharlan66]

DPS2,

We would need more information to make any recommendations.

What type of gear are you using?

If it is a BP is it AL or SS?

How much weight do you wear and where is it positioned?

Chad

 

[Uncle Pug]

DPS2 once bubbled...
I, too, am having a problem maintaining my trim... except that for me, my feet always want to sink.

What I am going to suggest is paradoxical and not intuitive... but bear with me.

Body positioning has a major effect on trim. Often we compensate for incorrect balance in the rig by unconsciously altering our body position.

For instance... a diver who is weight too heavy toward the head and has a tendency to go head first into the sand will compensate by dropping the knees and leaning back... this makes their feet sink and they think that they are foot heavy.

It is possible that you need to move weight back... ie. you are too heavy toward the head! The easiest way to find out is to experiment.

Move your tanks in the bands until they are as high as they can go... (as wreckwriter described.) With your height and weight I am sure that this is correct placement for you.

Then to test your balance... get suited up and head for the water... depth isn't important here but don't be in the surge as it will mask what we are trying to discern.

Get horizontal in the water and have your buddy check you to make sure you really are horizontal... that is thighs in a perfect plane with the torso... not dropping the knees... back slightly arched... and knees bent so that your lower leg is pointed straight up... you should be able to assume this position even if unbalanced.

Now tip your head down and look directly behind you. If you can't do this you are not horizontal... tip further over until you can look behind you. Now stop all finning and hand waggling (cross your ankles and hold your hands if you need to) .

What happens?

My guess is that before you even get to the point of being able to see under your belly and behind yourself you will start to topple over onto your head. If that is the case then you are too heavy at the head and the drooping foot syndrome is really a compensation mechanism.

IF this does indeed turn out to be the case then the solution will be to add a small amount of weight lower on the torso (not the ankles!)

However I think that with the tanks as low as they can go in the bands you should be close to right on.

You don't say... but are you diving cold water and wearing a weight belt ?

 

[ckharlan66]

Uncle Pug once bubbled...
Now tip your head down and look directly behind you. If you can't do this you are not horizontal...

If I did this the only thing I would see is my gut.

Chad

 

[Uncle Pug]

ckharlan66 once bubbled...
If I did this the only thing I would see is my gut.

How far does that thing hand down there anyway?
Or could you possibly turn your head to the side a little and look around it?

 

[ckharlan66]

Alot less that it use to. Thank goodness.

Chad

 

[Rick Murchison]

There seems to be a great deal of resistance to using ankle weights here. Especially when the problem is trim, ankle weights have the greatest moment arm available and therefore require the least weight to effect a change in trim if the problem is too much weight too far forward after moving the tanks as far down as possible in the bands and on the backplate.
Rick

 

[jbd]

and when Chad turns sideways and sticks out his tongue he'll look like a zipper

Actually he's almost DIR from a dietary perspective. Eating healthy and excercising.

 

[DPS2]

UP,

Thanks for that great info! I will certainly try that ... either at the lake or in the pool at my LDS and let you know how it goes!

By the way ckharlan66, my gear is a Dive Rite SS BP, Classic Wing, double PST 104's. No additional weight.

Thanks again for all the help!

 

[ckharlan66]

Try what Pug suggested and let us know how it goes.

Good luck.

Chad

 

[Uncle Pug]

Rick Murchison once bubbled...
ankle weights have the greatest moment arm

And resistance is a keyword as well.

Ankle weights add an unnecessary amount of resistance to movement by being out there on the ankles... and even if one only uses the frog kick... that moment arm still exacts a toll... but more so for the flutter kicker.

The weight movement necessary to effect a balanced rig can be as simple as moving the tank down... or wearing a weight belt that rides a little lower on the hips (as I do) or using that little half or quarter V weight that Tom referred to... none of which extract an energy penalty like ankle weights do.