Maintaining Trim while motionless

[topher10]

As a new diver, I have been working to improve trim and bouyancy control. I feel fairly confident in my ability to hold trim and depth, although with any task loading I can break trim and that is currently what I am working. For instance, staying fixed during a mask removal and replacement. The other issue is that if I become completely motionless I will slowly roll or break trim. Most recently I was slowly rolling to the left and back.

However, when I came back from my trip I started watching videos closely, and I notice that in almost all cases the diver is not completely motionless, but is slowly moving his/her fins back and forth. Often its small and just using the ankles, but there is a this more or less constant back and forth motion that helps maintain balance. I have watched GUE videos, ISE videos, random videos, etc.

So I have a few questions:
1. What is a realistic goal for holding trim/position with minimal movement? I assume no use of hands/arms, and very minor fin movements.
2. Is there a specific pattern or style for this small fin movement I see. In other words, is it specifically taught, or do divers just learn to do it unconsciously to maintain trim.
3. If one completely stops all movement, how long is a normal time before rolling/tilting occurs and trim breaks down.

 

[boulderjohn]

As a new diver, I have been working to improve trim and bouyancy control. I feel fairly confident in my ability to hold trim and depth, although with any task loading I can break trim and that is currently what I am working. For instance, staying fixed during a mask removal and replacement. The other issue is that if I become completely motionless I will slowly roll or break trim. Most recently I was slowly rolling to the left and back.

However, when I came back from my trip I started watching videos closely, and I notice that in almost all cases the diver is not completely motionless, but is slowly moving his/her fins back and forth. Often its small and just using the ankles, but there is a this more or less constant back and forth motion that helps maintain balance. I have watched GUE videos, ISE videos, random videos, etc.

So I have a few questions:
1. What is a realistic goal for holding trim/position with minimal movement? I assume no use of hands/arms, and very minor fin movements.
2. Is there a specific pattern or style for this small fin movement I see. In other words, is it specifically taught, or do divers just learn to do it unconsciously to maintain trim.
3. If one completely stops all movement, how long is a normal time before rolling/tilting occurs and trim breaks down.

Holding perfectly still is a pretty advanced skill. Don't worry about it now.

Th problem for you is that the kicking you are seeing in those films is more complex than it looks. It enables the diver to hold position. Notice it is not propelling the diver forward. If you just start kicking while holding position, you will probably move forward, either straight ahead or at an angle.

I suggest that if you have reasonable buoyancy and trim at this point in your diving life, begin to focus your learning into kicking technique. Work on the frog kick, the modified frog kick, the modified flutter kick, the back kick, and the helicopter turn. Get the hang of those. Eventually you may discover that you are, without realizing it, using a combination of several of them while you are trying to hold your trim, and you will find that this combination helps you hold your position.

 

[topher10]

Thank you, John. I appreciate the thoughtful advice. On my last dive while in shallow water I was working on holding completely still, and it is true that to remain in perfect trim I tend to always move forward slightly. I was in essence very slowly circling a spot as opposed to staying still. I notice that in the videos that there is a lot of lateral movement in the fins, similar to a helicopter kick. I see the value of getting better fin and movement control with different kick styles, and that eventually it will all come together with experience.

 

[tbone1004]

So I have a few questions:
1. What is a realistic goal for holding trim/position with minimal movement? I assume no use of hands/arms, and very minor fin movements.
2. Is there a specific pattern or style for this small fin movement I see. In other words, is it specifically taught, or do divers just learn to do it unconsciously to maintain trim.
3. If one completely stops all movement, how long is a normal time before rolling/tilting occurs and trim breaks down.

1. the ability to hover motionless is just as much about gear as it is about skill. I.e. no matter how good you are, if you have gear that is not trimmed properly, you can't hold a motionless hover. Anyone who tells you otherwise is lying. You can get VERY close, but to hold a perfect hover requires very accurate equipment balancing. An inch difference of cam band positioning can be enough to where you can't hold a motionless hover.
Now, the ability to maintain an essentially motionless however is mostly a skill thing. The kicking motion that you see in those videos are sculling motions not kicking motions. They are typically creating either upward or downward thrust based on the trim adjustments necessary. In sidemount that will typically be downward thrust, and in doubles it will be upward thrust. Sidemount typically is butt heavy, backmount is typically head heavy.

2. there is a very specific movement to the fins based on which type of thrust you are trying to create. It is all about creating lift the same way an airplane wing creates thrust. In backmount, you'll typically angle the leading edge of the fin slightly down which creates thrust in the upwards direction. In sidemount, you'll angle the leading edge upwards which creates downwards thrust.

3. it depends on how far out of balance your equipment is configured and how your body is able to react to it. The more out of balance the gear is, the faster you will go out of trim. I was double an unfortunately unbalanced set of doubles last week because the bands were set too low. I would lose trim in about a second if I stopped sculling. I adjusted the bands, and it would take about 5 seconds before I would get out of trim. Without a tail weight, I can't trim those specific doubles perfectly. Others can.

 

[topher10]

tbone: Thanks for the advice and answering each question. I initially came into this topic with the idea of rearranging weight to dial trim in since I couldn't hang motionless, but then I realized that everyone is finning/sculling slightly and so perhaps I am not as far off as I thought. If I hold completely still I tilt slowly, probably over a few seconds. To fix that last little bit might take a lot of work that is largely unnecessarily for my simple rec diving where I am moving most of the time anyway. So working on finning and movement control might be better to concentrate on for now. Plus I have a DSS BP/W and ocean dive with no additional weights in a 3m, so there is no real weight to move around. I am working on is trying to figure out exactly how high/low to put the tank. Its good to know that most people move their fins even when hovering, even if I am not quite good enough to do it.

Thanks again for the advice.

 

[Kevrumbo]

As a new diver, I have been working to improve trim and bouyancy control. I feel fairly confident in my ability to hold trim and depth, although with any task loading I can break trim and that is currently what I am working. For instance, staying fixed during a mask removal and replacement. The other issue is that if I become completely motionless I will slowly roll or break trim. Most recently I was slowly rolling to the left and back.

However, when I came back from my trip I started watching videos closely, and I notice that in almost all cases the diver is not completely motionless, but is slowly moving his/her fins back and forth. Often its small and just using the ankles, but there is a this more or less constant back and forth motion that helps maintain balance. I have watched GUE videos, ISE videos, random videos, etc.

So I have a few questions:
1. What is a realistic goal for holding trim/position with minimal movement? I assume no use of hands/arms, and very minor fin movements.
2. Is there a specific pattern or style for this small fin movement I see. In other words, is it specifically taught, or do divers just learn to do it unconsciously to maintain trim.
3. If one completely stops all movement, how long is a normal time before rolling/tilting occurs and trim breaks down.

My back begins to fatigue, and it aggravates a chronic pinched nerve condition in my neck -actively holding an extreme horizontal trim like the above picture.

Hold an active hard horizontal trim for as long as necessary along with proper frog & modified frog/flutter kicks as needed to pass low and close over a silty section of an Overhead Cave/Wreck for example, or with slight sculling back & forward frog ankle kicks to stay stationary, so as not to stir it up. Otherwise, the other option is to rise up higher off the silt and go ahead relax your back & neck, let the legs/knees & head/arms drop a bit but still passively hover above the silt (or open water reef/sandy bottom) while looking around enjoying/examining the scenery:

The idea in this "passive horizontal hover" is to adjust weighting so that the only relative motion is your whole body trim centered around your navel, moving slightly up & down as a unit during your nominal breathing cycles, instead of pivoting about your navel with your head & upper torso coming up & simultaneously knees/fins rotating down into the silt. In tropical waters with a 1mil skinsuit/3mil hooded vest and AL80 single/doubles sidemount, I needed 3kg/6lbs weight between my shoulder blades to counter my upper torso coming up during inhalation; In cold temperate home SoCal waters with a drysuit and AL80 doubles backmount /Steel BP&Wings, I use a 2.5kg/5lbs tailweight and heavy jetfins to counter the floaty drysuit feet & legs.

 

[tbone1004]

@topher10 most people have the tank too low on the backplate which will cause you to go feet down.

on the DSS plate, look at the lower of the two mounting holes in the top of the backplate. IIRC that's where the little rubber nubbin pushes through. That should be roughly 1" below the crown of the tank which puts the tank in roughly the same position as doubles. Good place to start

 

[AJ]

Motionless trim is a combination of body tension, skills and gear setup. But to be honest, the most important kick in staying motionless is the back kick.

I don't think anyone will ever achieve complete motionlessness in diving. You can get close, but when doing a valve drill for instance, almost all will propel themselves forward. That's where the back kick becomes the most important kick. It enables you to stay at your position relative to the team while doing drills.

 

[Neilwood]

One thing that can help is body position once in reasonable trim - use the arms and legs as a lever.

Think of your body like a see-saw (teeter totter for you Yanks). The idea is to get both ends in equilibrium. Fortunately you can do that with your body. If you try to dive flat, you have a lot of weight at both ends of the lever. Trying to get into the "skydiver position" can help

You can offset some trim by the position of your hands (which should be doing almost nothing anyway). Holding them in different positions in relation to your body ie closer in or further out) can alter the pivot action

Moving your feet up and down from flat trim to a modified flutter/frog kick position (ie bend your knees up to 90 deg).

By tweaking the exact position of your hands and feet, you can go some way to helping get trimmed. The pictures in this link show it fairly well (link)

 

[DiverDownD3]

Thanks to the OP for starting this thread and those responding. As tbone mentioned I am one of those that struggle to get my feet up. I usually end up in the "relaxed" position that @Kevrumbo mentioned above. I'll have to play with tank position. I lost 20 lbs this winter, so I was all over the place when I went diving the other day, amazing what getting rid of a bunch of fat will do.