The Vagaries of Trim

[Ste Wart]

This weekend I offered to do the video work for a Fundies class. I was pretty much wearing exactly the same kit that I had recently passed Fundies in, bar going to back to my Mares Avantis.

The results were less than fabulous. :shocked2:

Without the heavy sold fins I was unable to properly trim out, I had trouble dumping gas from the kidney dump and my knees were dropping all the time, plus my back kick had vanished. Not such an issue as I wasn't the focus, however I was somewhat annoyed.

The following day I borrowed a friends Hollis F1s and it was like I was a different diver. Trim was effortless, back kick returned and the kidney dump vented gas as per usual.

So was this an equipment fix for what was essentially a skill problem or is it case of wearing the right equipment?

 

[Subcooled]

You have some air in the legs of your drysuit. If you replace good fins (rubber fins, popular since 50 years ago, and still going strong) with plastic fins, then your feet become more floaty. Keeping the feet up is a very unstable position as you really cannot remove all air from your legs because of the undergarments. You work like a scale: Heavy end. Light end. Tilt.

This issue must be compensated for (more air in arms) and very very easily one gets afraid of keeping the feet up (because that position is very unstable).

You want to keep the feet down. This means that you are not in horizontal position and the back kick becomes impossible.

Hey, if something has been left unaltered for half a century, and it is still hugely popular,
then only an idiot would say that something that gets altered every 6 months is superior.

 

[TSandM]

It's proper use of equipment. You can't fight physics; if your static balance is sufficiently off, you can compensate, but at the cost of constant motion or incorrect trim.

 

[aprivetera]

Equipment is a key factor. In the beginning, I had a lot of trouble improving my trim (and staying there) until I switched to back inflation and rubber fins, the latter definately being a bigger factor. Every once and a while I throw on rental equipment because someone wants to try my setup and its torture.

 

[j2s]

Tanks (band placement on tanks and tank size) bp (bp placement on tanks) wing (wing placement on bp/tanks) fins, wet suit, dry suit...It's all going to effect trim......

 

[PfcAJ]

I think it's probably a lil of both. You sub'd out fins that aren't working for you at the moment. I'd venture a guess that eventually, you'll be able to dive both fins equally well. But that time is just not now.

Stick with the heavier ones.

 

[Ste Wart]

I think it's probably a lil of both. You sub'd out fins that aren't working for you at the moment. I'd venture a guess that eventually, you'll be able to dive both fins equally well. But that time is just not now.

Stick with itch the heavier ones.

The Mares ebay listing is one click away. I think my 11 years of plastic fin use is effectively over

 

[dbulmer]

The Mares ebay listing is one click away. I think my 11 years of plastic fin use is effectively over

Assimilation is an on going process - just seems to take longer for some folks

 

[budgy]

If you were teaching a novice with a foot light trim balance problem I'd expect you'd be telling them to try arching the back a little more and drop the hips and extend the neck a touch, instead of messing them around with ankle weights, or lowering the cylinder below their bum. You know most people in a dry-suit are able to adjust their posture enough to achieve horizontal trim with Mares polymer fins. Compensating may feel a little funny at first, but it soon passes. Get with the program, lets see a little more cat walk model posture, if you please!:blinking:

 

[tracydr]

Do you feel like you have some excess air in your feet? Some fin keepers could help. Otherwise, I'd say just stick with a heavy,rubber fin.