Best Method for Achieving Trim

[MichaelMc]

That is correct, I am cave trained. On a cave dive, its not uncommon to end up with stages that have a 4lb buoyancy shift. Maybe a few of them. Then maybe you'll pick up a heavy deco bottle. Maybe a scooter. Imagine if every time I picked up or dropped gear I'd have to re-work my weight configuration. That'd be just nutty.

Instead, I choose to dive the gear. I (and you) can make subtle adjustments to body position to allow for effortless trim. To me, this is FAR superior than being reliant on equipment to make my trim for me.

I assume you are diving dry? Maybe with heavy fins? A comment Storker made above comes to mind. Your trim affects your trim, or rather your center of buoyancy given the location of any suit bubble. I'm diving wet, and with neutral fins, and maybe neutral legs given my suit. So for me position does not change the location of my lift or negativity very much. It does some, but not a lot. Arms in and out does change things. As does corrective finning. So I think I have (much) less ability to shift air around in water than you. And my buoyancy is dialed and we dive fairly shallow so there is less air in the BC to shift.
All those gear changes without that suit on might be different. Though I have some wing air shifts.
And weights dialed very fine for you likely make little difference over the air shift of a few degree down or up trim, or legs up or down a bit to shift air (not sure about the leg air stuff).
The OP is diving wet or dry depending.

 

[PfcAJ]

I assume you are diving dry? Maybe with heavy fins? A comment Storker made above comes to mind. Your trim affects your trim, or rather your center of buoyancy given the location of any suit bubble. I'm diving wet, and with neutral fins, and maybe neutral legs given my suit. So for me position does not change the location of my lift or negativity very much. It does some, but not a lot. Arms in and out does change things. As does corrective finning. So I think I have (much) less ability to shift air around in water than you. And my buoyancy is dialed and we dive fairly shallow so there is less air in the BC to shift.
All those gear changes without that suit on might be different. Though I have some wing air shifts.
And weights dialed very fine for you likely make little difference over the air shift of a few degree down or up trim, or legs up or down a bit to shift air (not sure about the leg air stuff).
The OP is diving wet or dry depending.

Sometimes wetsuit, sometimes drysuit. sometimes no suit. sometimes a thin undergarment, sometimes thick. Sometimes xl jetfins, sometimes large jets. Sometimes OC, sometimes RB. Sometimes al80s, sometimes lp120s. Gosh, sometimes I've got a steel 72 and a horse collar bc! Sometimes I end up with a jacket bc and full foot fins if I'm traveling.

It. Doesn't. Matter!

Get it close and get on with it.

There's a million permutions you might find yourself in. The only common factor is you.

 

[sea_otter]

Instead, I choose to dive the gear. I (and you) can make subtle adjustments to body position to allow for effortless trim. To me, this is FAR superior than being reliant on equipment to make my trim for me.

It takes a while to build that level of proficiency, though. I'm finally starting to get it myself. I had a very good instructor who would offer what he called "pacifiers" to students who were struggling with head heavy trim - a 6 lb weight on a cam band strapped around the bottom of a single tank. It was a huge help for me, and I used a similar setup for many dives after his class. As I've become more comfortable with my own body position underwater, I find it is no longer necessary.

Gorilla tape and rubber bands sound a bit crazy, but hey, it likely makes diving easier and more enjoyable. You can call it a pacifier or a crutch, but if it works, I can't see the harm in that. Eventually the hassle of dealing with all the silly pacifiers exceeds their worth, at which point you can do away with them. Until then, I say why not?

 

[PfcAJ]

It takes a while to build that level of proficiency, though. I'm finally starting to get it myself. I had a very good instructor who would offer what he called "pacifiers" to students who were struggling with head heavy trim - a 6 lb weight on a cam band strapped around the bottom of a single tank. It was a huge help for me, and I used a similar setup for many dives after his class. As I've become more comfortable with my own body position underwater, I find it is no longer necessary.

Gorilla tape and rubber bands sound a bit crazy, but hey, it likely makes diving easier and more enjoyable. You can call it a pacifier or a crutch, but if it works, I can't see the harm in that. Eventually the hassle of dealing with all the silly pacifiers exceeds their worth, at which point you can do away with them. Until then, I say why not?

Ya, I suppose its ok as a temporary thing for learning purposes. But that's not where we're at in this thread.

The point remains that you don't *need* those things. You even said that you don't use it now because you developed your skills to do without. That's what I'm about. Develop skills so you don't need extras and doodads.

If you never push to get away from those doodads you'll be reliant on them forever. You broke free of that pacifier and that's good. Id like to see everyone do that.

 

[MichaelMc]

It takes a while to build that level of proficiency, though. I'm finally starting to get it myself. I had a very good instructor who would offer what he called "pacifiers" to students who were struggling with head heavy trim - a 6 lb weight on a cam band strapped around the bottom of a single tank. It was a huge help for me, and I used a similar setup for many dives after his class. As I've become more comfortable with my own body position underwater, I find it is no longer necessary.

Gorilla tape and rubber bands sound a bit crazy, but hey, it likely makes diving easier and more enjoyable. You can call it a pacifier or a crutch, but if it works, I can't see the harm in that. Eventually the hassle of dealing with all the silly pacifiers exceeds their worth, at which point you can do away with them. Until then, I say why not?

The point remains that you don't *need* those things.

Diving wet, or no suit, and adding stages and scooters, what is the physics of how you are staying in a stable trim? (I should know, I do dive wet.., though not with as big changes.) Arms and legs in and out to shift the center of buoyancy, to a point. And then slight changes in them or slight finning, not to try to counteract remaining imbalance between center of negativity and center of buoyancy, but rather to hold an angle that puts the air bubble in the wing to the point where those two are aligned?? Or at least oscillate around that angle? Or maybe more shoulder and hip angle changes to achieve that relative to arms and legs that stay, temporarily, a bit more fixed against the water???

 

[dumpsterDiver]

Ya, I suppose its ok as a temporary thing for learning purposes. But that's not where we're at in this thread.

The point remains that you don't *need* those things. You even said that you don't use it now because you developed your skills to do without. That's what I'm about. Develop skills so you don't need extras and doodads.

If you never push to get away from those doodads you'll be reliant on them forever. You broke free of that pacifier and that's good. Id like to see everyone do that.

Your comments in this thread go 180 degrees from 95% of the stuff on this forum. There are endless discussions of finding perfect trim, moving one pound here or there, getting the perfectly weighted fins and optimizing all for a particular tank(s).

I pretty much shut up about all that and since i dive several different tanks and different wetsuits and sometimes wear none, sometimes I need a weight belt -other times not, so with all these changes, my ability to "fine tune" trim or weighting is not there. So it is interesting for me to hear you say "just deal with it"..

On the other hand, when I used to wear a 7 mm FJ, 7 mm step in jacket a 3 mm hooded vest and a 5 mm hood while wearing an aluminum tank and a recreational BC, my chest buoyancy with all those layers of rubber was a real annoyance. I started hanging a 2 lb weight from each side of the shoulder straps, on the front, right by the quick release clips. It made a huge difference in comfort, so I think it might be reasonable to move weight around some, in order to get things at least close to comfortable.

 

[PfcAJ]

Diving wet, or no suit, and adding stages and scooters, what is the physics of how you are staying in a stable trim? (I should know, I do dive wet.., though not with as big changes.) Arms and legs in and out to shift the center of buoyancy, to a point. And then slight changes in them or slight finning, not to try to counteract remaining imbalance between center of negativity and center of buoyancy, but rather to hold an angle that puts the air bubble in the wing to the point where those two are aligned?? Or at least oscillate around that angle? Or maybe more shoulder and hip angle changes to achieve that relative to arms and legs that stay, temporarily, a bit more fixed against the water???

I think a lot of it has to do with legs in or out, arms in or out, head position, and core activation. I also think that minor (maybe even imperceptible to an outside observer) changes can make a noticeable impact on your body position and comfort.

To be clear, I'm not suggesting to just totally abandon all consideration of where your weight goes. Obvi if someone straps a 10lb weight to my foot I'm not going to be Captain Flattrim. I'm sayin' that 1lb changes here and there aren't a good solution.

 

[PfcAJ]

Your comments in this thread go 180 degrees from 95% of the stuff on this forum. There are endless discussions of finding perfect trim, moving one pound here or there, getting the perfectly weighted fins and optimizing all for a particular tank(s).

I pretty much shut up about all that and since i dive several different tanks and different wetsuits and sometimes wear none, sometimes I need a weight belt -other times not, so with all these changes, my ability to "fine tune" trim or weighting is not there. So it is interesting for me to hear you say "just deal with it"..

On the other hand, when I used to wear a 7 mm FJ, 7 mm step in jacket a 3 mm hooded vest and a 5 mm hood while wearing an aluminum tank and a recreational BC, my chest buoyancy with all those layers of rubber was a real annoyance. I started hanging a 2 lb weight from each side of the shoulder straps, on the front, right by the quick release clips. It made a huge difference in comfort, so I think it might be reasonable to move weight around some, in order to get things at least close to comfortable.

I see those posts you're referring to. I think they're silly.

Youre correct about getting things *close*. You might be well served by some minor adjustments, and there's nothing wrong with that.

 

[MichaelMc]

Your comments in this thread go 180 degrees from 95% of the stuff on this forum. There are endless discussions of finding perfect trim, moving one pound here or there, getting the perfectly weighted fins and optimizing all for a particular tank(s).

I pretty much shut up about all that and since i dive several different tanks and different wetsuits and sometimes wear none, sometimes I need a weight belt -other times not, so with all these changes, my ability to "fine tune" trim or weighting is not there. So it is interesting for me to hear you say "just deal with it"..

On the other hand, when I used to wear a 7 mm FJ, 7 mm step in jacket a 3 mm hooded vest and a 5 mm hood while wearing an aluminum tank and a recreational BC, my chest buoyancy with all those layers of rubber was a real annoyance. I started hanging a 2 lb weight from each side of the shoulder straps, on the front, right by the quick release clips. It made a huge difference in comfort, so I think it might be reasonable to move weight around some, in order to get things at least close to comfortable.

I'll go reread them. Thanks.

 

[sea_otter]

Ya, I suppose its ok as a temporary thing for learning purposes. But that's not where we're at in this thread.

Aren't we, though? The common complaint here is having to constantly scull with fins to stay in trim. I know that feeling well, and it's a tough one to move past. If you can fix it with gear, then you can learn to relax and keep your fins quiet, and from there it's much easier to start making those fine tune adjustments with your body instead of your gear. That's a darned difficult thing to figure out if you're struggling just to stay horizontal in one place.