Body Positioning/Trim Issues

[TSandM]

If doubles solved your problem, I suspect your original issue was that you didn't have enough weight on your back (or too much weight too low, is another way to say it). Doubles do two things -- they increase your stability by increasing your inertia, and they shift the center of gravity way up. Most of us found, when we switched, that we had to learn to balance being head-heavy in doubles. If you didn't, you were probably feet-heavy in your single tank setup.

 

[lamont]

Just something I am adding on to this post. I frequently see people in position C while out diving (Dave's trim is very much like that), and on youtube. For instance here: Frog Kick - YouTube

You do frequently see that position, but its incorrect. The body position is okay, but the trim is off and the fin tips are pointed down and in a cave you'd see constant little silt devils whirling off those kicks in the silt behind the diver.

i can also feel the difference in stability when i get locked into proper trim and i'm not finning down like that and pushing myself up, so even outside of a cave this will make for a less stable platform for the diver in open water conditions.

Plus when the unstressed trim is like this, this is an indication that under stress the diver is likely to drop to even worse trim and drop their knees and any stability is going to suffer.

This guys seems to have the arched back thing going on, and his feet are about level with his head. Same for the guy in this video: DIR Modified Frog Kick - YouTube
And I know I personally feel much more in control when I am trimmed like that.

Thats much more correct, the direction water is propelling off the fin tips is back and not down. You can even go slightly more head down than that and get the top of the tanks perfectly flat. I tend to shoot somewhere between the top of the tanks perfectly flat and the position in that video. A lot of divers will shoot for barely making the position in that video with a lot of effort and then will relax into the position in the first video when they're not being attentive or being task loaded (which is why you see a lot of that trim), and those divers will tend to drop to 30-40 degrees out of trim when they're task loaded (which makes a course like tech1 very difficult and you'll wind up with remedial fundamentals days or all kinds of buoyancy issues popping up and down since you need trim first before you can get a stable platform). If you shoot for a flat-tanks zero trim and can hold that with some difficulty, then when you relax you should nearly always have trim like that video and will only occasionally fall into a lazier trim position and that makes tech diving and tech courses easier.

And the advice you should probably be getting is to alternate between your A and B positions depending on what you are doing. A is good when you are at a stable depth or hovering, but as you ascend then you will tend to get gas bubbles in your feet, so you'll need to adopt a position more like B and then roll and break trim and dump. And you should be 'doing that dance' a lot. If you are doing an ascent (say 1 minute stops from 50 straight to the surface or something) then you'll probably want to look more like B than A so that its easier to keep gas out of your feet and migrate it out.

Neither of them are the 'right' answer, but I do know that I spent about 100 dives doing 'B' a lot at first and stretching out, since it does avoid gas in your feet, then I got better at alternating based on what I was doing.

And similarly there's no right answer for suit-vs-wing. I tend to use my suit up until the point where I get a suit bubble and then need to shift it to my wing. Suit is actually primary for me to fiddle with, while wing is secondary for managing the suit bubble. If I'm diving off the bottom of my tanks then I may have zero gas in my wing and only be diving the suit. As the amount of gas I'm carrying increases (full doubles of 32% would be a lot of extra negative weight) then I'll need to add more gas to the wing and will need to fiddle more with wing/suit shifting -- with full large doubles like hp130/hp119s/lp104/lp95 of 32% then you should be doing a lot of shifting gas between the wing and suit, but that's sort of telling you that you're doing it wrong -- double-130s are for trimix, and the small dubs should be used for 32% for redundancy at rec depths.

 

[mdb]

You seem to be in great "Trim". I'm sure you will have much additional advice from all the trim experts.

 

[Superlyte27]

Agree with you. However the OP has 125 dives. Just when does it stop ..."Being in proper trim DOES NOT usually feel good at first"? He past at first a while ago. In fact I find it rather strange with that many dives the op is asking such a question.

I'm sorry, in my opinion 125 dives is still a baby. Especially if he is only now looking at proper trim, which is often the case. I was a boat captain and dive master, later an instructor in Key Largo. Of the thousands of people I've seen in the keys, some diving for decades, what percentage do you think were actually in trim? I'd guess less than 30%.

So, I reiterate.... being flat in the water, with your back straight, fin tips up, neck bent as far up as it will go, feels awkward at first.

---------- Post added ----------

When I dive dry I use my suit for buoyancy control while underwater, and my BP/W on the surface. This way I'm only controlling one system at a time..

Terrible method in technical diving. Your drysuit was designed for warmth primarily. REDUNDANT buoyancy was just a convenient bonus. Your wing on the other hand is designed to keep you in trim regardless of the volume of gas in the wing. Put a tiny bit of air in your wing, put all the air in your wing, your trim does NOT change. Try that with a drysuit.

---------- Post added ----------

Interesting that PADI courses say exactly the opposite According to PADI, you should control your buoyancy through dry suit while under and with BCD while on the surface. That paragraph does have a caveat -- it is valid for all but technical dives as technical diving requires substantially more gear / weight thus suit alone is insufficient.

My personal position with dry suit (based on those diagrams) is

1) descent: almost always - A
b) ascent -- A or B:

I use B when coming up to ~20 - 25' since (at least for me) this seems to be the most difficult area to maintain proper buoyancy and to control rapidly expanding air bubble in the dry suit (if it does bubble to your feet instead of shoulder valve @20 feet, you might not have enough time to roll to get air out of your suit legs. For deep to ~25' I try to come up in position "A" WITH my left arm/shoulder (which is where the valve is) slightly above my torso with an elbow bent to prevent air from going into my wrist area.

Also, I found that I don't need to really add air other than to control the squeeze if properly weighted. If I maintain the same suit volume as on the surface (i.e. squeeze vs. added air) the rest of control comes from inhale / exhale part.

If you are trusting PADI for your technical instruction, that's your first mistake. The PADI book is wrong if it's saying the drysuit is your primary means of buoyancy, as it was NEVER designed to keep you in trim.

 

[tflaris]

I have about 125 dives now, and for the last 60 or so, my trim has been pretty good. However I seem to have hit a standstill. I cant seem to make it feel "perfect" underwater. I believe my weight distribution is solid, so I am fairly certain that it is the body positioning that I cant seem to figure out. I see videos of people in proper trim, but everyone seems to do it slightly differently. So I found a drawing of a diver in trim, and I edited it twice to resemble 3 different poses that I commonly see in videos describing what good trim is supposed to look like.

View attachment 124644Here it is.

So which one of these is "proper trim"? One of them? All of them? I see A most frequently. However when I find myself in that position in the water, I cant do a good back kick. I also find that position to be highly unstable for me. Having my feet that far above my head makes me feel like I am upside down. No I do not get vertigo, but it just feels completely wrong in the water. And to do the aforementioned back kick, I have to drop my legs into position C. I cant seem to get enough power from position A.
Furthermore, I am having trouble dumping air from my drysuit. When my feet are above my head like that, almost all the air goes into my feet. When I go up even a few feet, it starts to pull something fierce, so I am forced to break trim completely and go vertical in the water in an attempt to vent my suit. While I do this, all the air rushes up to my shoulder area and makes me ascend a few feet. Eventually I get the air out and sink back down. However once I get back in trim, since the air is now more evenly distributed (a tiny bit in the chest/hands and a lot in the feet as opposed to all in the shoulders), I am now negative. Then I have to add some air to my wing to pick myself back up. I expend waaaaaaay too much effort in doing this little dance constantly every few feet. FYI I am only adding enough air in my suit to create loft. This is part of the reason I am having trouble getting air out of my suit (even with the valve all the way open). The air in my suit isnt creating enough pressure to escape the valve, even when all the air is in the shoulders. For this reason I am hesitant to take any weight off my rig, even though I think I can afford to be a couple pounds lighter.
It wasnt long ago that I would use my suit only for buoyancy control. Many people have told me not to do this. Yet I never had any issue with that. My buoyancy was a thousand times better doing it that way because I didnt have to do this f***ing dance every few feet. I had all the air in my suit, so it never had any trouble escaping the valve, meaning I could just turn to my side slightly and let a little trickle out.

In summary:

1. Which of those pictures, if any, represent proper trim?
2. Does anyone have any body positioning tips I can use...?
3. ...or a solution to my dumping issue?

Any help is appreciated

Dylan

Short and sweet as possible:

Top picture horizontal trim using modified frog kick

Middle picture horizontal trim using frog kick

Bottom picture the diver is leg heavy dropping the knees.

When at rest you should be as horizontal or flat as possible. If you are tilting head down then a simple solution is the slide the wing forward (assuming double cylinders). Or slightly move the cylinders down but be aware this may affect your ability to reach your manifold. Or try heavier fins.


Hope this helps


---
I am here: http://tapatalk.com/map.php?kx4ovp

 

[TSandM]

Middle picture horizontal trim using frog kick​

I was taught this frog kick with the leg extension component by a GUE instructor, as a way to get additional power and keep the fin tips down. In a later class, another GUE instructor took grave exception to that and wanted NO leg extension component to the kick at all. And I have to say that, over some of the truly evil sediments I've met in Florida, I don't want any leg extension, either

 

[Griffo]

Great thread, lot of information here.
I'm pretty sure I look like picture C most of the time still. Trying like hard to look like picture B but my lower back gets sore and my glutes always seem to give up about 30 mins into the dive.

Does anyone have any tips for helping with that apart from "dive more" ?

 

[Superlyte27]

What's your rig? Are you bcd or bp/w? Are you using steel tanks or aluminum tank. Are you singles or doubles/

When your rig is right, you can just stop moving and hang perfectly flat without effort.

 

[Griffo]

What's your rig? Are you bcd or bp/w? Are you using steel tanks or aluminum tank. Are you singles or doubles/

I've just done Fundies (rec) with steel singles and wet. That should answer all your gear questions.

When your rig is right, you can just stop moving and hang perfectly flat without effort.

I can hang there, but my knees tend to drop, I need work work to keep my knees up, I have to work the entire time to "hold them up" as it were. Maybe it's just a by product of sitting at a desk all day.

 

[TSandM]

It takes a while to develop the muscles to keep your knees up all the time, and I'll admit that, when I'm away from the bottom, mine droop just a little bit -- not so it breaks the line of the lower body, but just enough to be comfortable. Close to the bottom, I'm much more mindful of keeping them up, up, up.