Trim in midwater

[TSandM]

Okay, I've sat on my hands for three days, but I can't stand it any longer.

I've been in caves. I understand trim and non-silting in a cave or a wreck, where viz is critical, tolerances are small, and any mistake can make a routine exit into an unpleasant adventure.

But what is the utility of perfect trim in a midwater ascent?

I understand the concepts of horizontal ascents and decompression. I'm not talking about going vertical. I'm talking about 20 to 30 degrees off horizontal. Is there really any practical issue with it? (It seems as though it makes venting the drysuit enormously easier, among other things.)

 

[MonkSeal]

Just a couple of things:
1. Less drag when moving horizontal and all consequences that come from this (less effort, lower CO2 build-up, lower SAC, etc.)
2. Better situational awarenes - when you're in trim you don't sleep
3. Better control
4. Easier to dump wing
5. Trim becoming second nature to be prepared for silty environment
6. ...

 

[Sloth]

On ascent up to 15 feet or so I don't feel comfortable unless I am in good trim. After 15 feet or so I usually get out of trim so I can track the boat and other divers better.

Why the itch to get out of trim when you spend 90% of your dive in 0 degree +/-5? Just curious.

 

[TSandM]

No "itch" to get out of trim. I just failed my Rec Triox reeval dive for failure to maintain flat trim during ascents. And although I am not arguing that standard aren't standards or that I should have passed, I'm just frustrated by being unable to explain the utility of perfect trim on ascent. The issue of drag while swimming doesn't come into it, as you are on deco and floating. You may perhaps have slightly better control, but again, I'm not talking about vertical here, just a little out of trim.

Anyway, from information I've gathered, it appears that this is a BIG deal, and I just want to wrap my brain around why. One of the thing I like most about DIR diving is that things have reasons, and I just don't understand this one.

 

[nadwidny]

If you get a drysuit or BC start to self inflate a horizontal position makes it easier and quicker to go head down.

 

[JeffG]

But what is the utility of perfect trim in a midwater ascent?

Is this what you are talking about?

Because if so, I don't see a problem with it.

It doesn't stop me from doing anything and its comfortable.

 

[MonkSeal]

Anyway, from information I've gathered, it appears that this is a BIG deal, and I just want to wrap my brain around why.

Then ask your GUE instructor to explain you That's his job.

 

[JeffG]

Then ask your GUE instructor to explain you That's his job.

My understanding is that is what the problem is. Not passing her based on her "trim" and yet if she is able to demonstrate any and all emergency skills...then this "out of trim" issue, shouldn't be an issue.

 

[MonkSeal]

My understanding is that is what the problem is. Not passing her based on her "trim" and yet if she is able to demonstrate any and all emergency skills...then this "out of trim" issue, shouldn't be an issue.

There are requirements, standards, expectations etc. One of them is to stay in trim while doing something (drills, deco, whatever). If you comply with it you'll pass. The question was why it's a BIG deal to maintain perfect trim during midwater ascent. I'll throw another:
6. Good trim makes keeping neutral bouyancy easier which is important when switching (identify, deploy, check depth, breath).

 

[Steve R]

My understanding is that is what the problem is. Not passing her based on her "trim" and yet if she is able to demonstrate any and all emergency skills...then this "out of trim" issue, shouldn't be an issue.

Why is it I get the feeling that this trim issue must be worse than what we would like to believe?

Honestly Lynn, between you and Peter and all your worri-some questions and threads, I think my best advice would be to chilax a bit and just go diving for the sake of the fun of it, for a change.

If you know what it is you're doing not as well as you'd like, and you know how to fix it, which I am sure you do, then just go diving. To me the biggie is Monkseal's point, just above my post.