Another trim question....

[bperrybap]

Maybe what he means is being vertical in the water column.

The very first sentence of the original posts states why
he was standing.....

--- bill

 

[JeffG]

The very first sentence of the original posts states why
he was standing.....

--- bill

and Jason was quoting GDCB. Someone who isn't the original poster.

 

[Charlie99]

Reading the original posters follow up comments, it seems that he is still trying to get into the right ballpark, and is probalby also out of balance in the head to toe direction., as well as front to back. Head to toe should be sorted out first, and only then does my advice about moving weights towards the front/belly make sense.

How about when taking a picture or doing a specific task. I think any position should be maintainable.

I find that once I get center of gravity and center of buoyancy reasonably close, then I can indeed take ANY attitude, including weird combinations of pitch and roll and stay in one spot while motionless.


If you have air in the wing or BCD, the air bubble in the wing or BCD shifts position as you roll and pitch such that however you stop, that is where you'll stay. Since the air bubble is above you, the shift in position of the air moves the center of buoyancy in a way that aids stability. This, of course, is only once you gets close on your adjustments.

Because of this, I found that the final tweaks on weight placement and distribution was best done with a near empty tank and no air in the BCD. With a full tank, or at depth with wetsuit compression, the air in the BCD just makes things more stable.

 

[Scotty g]

Yes it certainly appears that it's a central point of gravity issue. My belt covers 75% of the rear of my body (25% being an even opening from my belly button outwards in either direction).

I am very comfortable in my trim and my instructor/divemasters have all commented that my streamlining is extremely good for a novice. Like i said, my only issue is when i stop finning and cannot seem to help my feet coming forward and my upper body rolling back so that i end up in a sitting position (like on one of those race car simulators in an amusement arcade). I end up flapping my arms trying to gain balance and get my feet back under me (behind me) so that i can start to maintain 'belly down' position again.

My reasoning for 'standing up' on the platform is nothing logical. I could have knealt down i guess but my instructor didn't seem to have a problem with me descending to a standing position on the platform. I guess that i could have knealt down a few moments later but shouldn't i have been able to stand up initially without this 'tumbling' effect going on?
Scotty

 

[Scotty g]

Scotty,

It might be better to assess your trim when you are not moving. In other words, float at mid water and see if you can keep that horizontal trim without moving your arms or finning.

http://forum.5thd-x.com/viewtopic.php?t=978

HTH

Hi Adobo,

Yes i have tried floating mid water without finning and my horizontal trim goes to pot and ends up with my feet eventually coming forward and results in me flapping my arms trying to gain a horizontal 'belly down' trim again.

Scotty

 

[Adobo]

Hi Adobo,

Yes i have tried floating mid water without finning and my horizontal trim goes to pot and ends up with my feet eventually coming forward and results in me flapping my arms trying to gain a horizontal 'belly down' trim again.

Scotty

Keeping horizontal trim while swimming is pretty simple. In fact, a lot of times swimming will mask whatever trim and bouyancy issues you might be having. This is not a good thing since masked problems tend to present themselves at the most inopportune times. If you are finding it difficult to maintain horizontal trim while not swimming, then the article I pointed out will help you diagnose and resolve your issue.

Most likely, you will need to move some weight closer to your head. Keep in mind that there is a lot of bouyancy north of your center of gravity to start with. Your lungs, you BCD (particularly if it has a lot of padding), a sizable portion of your exposure protection, are all located north of your COG. Having all of your weight on your hips, which I believe is just south of your COG, will cause you to have the problems you are describing.

 

[Jason B]

The very first sentence of the original posts states why
he was standing.....

--- bill

Actually the first sentence states that he was told to descend to the 22 m platform. It didn't say he was told to stand, sit, kneel or hover. In fact, the OP never says why they were standing.

Just to refresh your memory....

Doing my AOW recently i was asked to descend to the 22m platform. Once i got there, i 'stood' on there (not kneeling) and felt as if i was being blown backwards with a light breeze (it was a quarry dive).

I was addressing a different post where someone was responding to a post by TSandM (who was responding to the OP).

 

[GDCB]

What on earth are going to be doing that requires you to satand up while underwater?

I doesn't matter what the task might be. Just that it should be a doable skill. Just for kicks let's say maneuvering into a structure or freeing up the anchor or rising in a confined space or taking a picture in a crevasse. Who knows... you should be balanced.


Carl

 

[TheFoggyMask]

In my professional opinion, your trim sucks. Try to be better in the future.

 

[Scotty g]

In my professional opinion, your trim sucks. Try to be better in the future.

Yep i'm sure that when i get to your level then yes, i could possibly get the hang of it by then. Dude, surely a man of your calibre should be out saving the world these days?