Having trouble hovering level, any suggestions?

[DevonDiver]

There is a lot of chatter here about trim...but it seems people are overlooking the obvious...

The most common cause of feet down/head up trim in the water is caused by over-weighting,

Think of your center of gravity (CoG) in the water. It is on your mid-line, somewhere between your navel and sternum.

Where are your weights located? Typically they are lower than your CoG...around your hips. They pull your lower body down.

To compensate for the weight...what do you do? You add air to your BCD. Where is the air accumulated? Around your upper torso....higher than your CoG....It pulls your head upwards.

The more weight around the hips....the more you need to add air around your upper-torso....and the more pronounced the push-pull effect across your CoG becomes.

If you get your weighting right (properly right....not just what you think is right) - you will have less weight pulling your lower body down...and less air in your bcd which pulls your upper body upwards.

 

[Colliam7]

My feet want to go down and my body up. I seem to be able to control it a little with shallower breaths and it doesn't seem as big of a problem while I am moving forward, but I want to hover!

Weight and trim management in diving is very much like weight and balance management in aviation. You must be properly weighted (in particular, not overweighted), AND your center of gravity should be at a point to allow you to remain reasonably horizontal while resting in the water. You are not alone in your dilemma. I had an AOW student last weekend with the very same issue (who also happened to be diving a Ranger), and I went through a series of assessments and corrections with him. Several posters have already mentioned steps to be taken to address the issue, and I will take the liberty of building on their good suggestions.
1. Do a proper weight check (tank at 500 PSI, BC deflated, hold normal breath, release breath, etc.) and make certain your are properly weighted. As BlancoB suggests, more than a few divers, particularly newer divers, start off overweighted, and trim problems develop as they attempt to compensate for the weight burden. 2. After you are properly weighted, submerge and attempt to hover in ~10 feet of water (nothing magical about the depth, just give yourself enough clearance above and below to maneuver). Breath normally, and stop ALL hand and foot motion. Determine if you are rotating to a vertical, foot down position, when you are motionless. This may be hard, because many divers tend to engage in some level of ‘station keeping’ – sculling a bit with hands or feet, or even kicking, without realizing they are doing it. Allow yourself to rotate to whatever position your weight and trim takes you to, to better understand what changes you might need to make. One observation on this step:some divers seem to be initially uncomfortable with a truly horizontal psoition, and sense that they are 'head low' when, in fact they are horizontal. It takes getting used to for some. As H2Andy pointed out, 'don't be afraid to adopt a slighlty "head down" attitude'.
3. If you are, indeed, still ‘foot heavy’, shift weight toward your head.
a. Move the tank higher (as noted, move the BCD lower on the tank).
b. Shift weight higher, from the BC weight pockets to a higher point on your torso. You can use some trim weight pockets as several have suggested, attaching them to the upper cam band on the Ranger. Or, you can even take a set of ankle weights clipped together, and hang them around the neck of the tank. I find the Ranger may have a tendency to move you to a slightly foot down, vertical position, because of the (front) position of the weights.
c. You might try a lighter / more buoyant pair of fins. You don't mention what fins you use, but if you are using ScubaPro Jets, for example - a negatively buoyant fin, you might try a different, less negative fin to see what happens. d. I find diving a stainless steel backplate instead of my Ranger helps as well, but that is just a personal preference.

In the midst of a dive you can even try swimming with a potato size stone in each hand. You will be slightly over weighted for the moment but it will give you tangible feedback about the see saw you are seeking to balance.

This can be a very useful diagnostic technique. In fact, since you are diving a weight-integrated BCD, and have access to soft weights, you might try keeping 2 lbs out of your BC, and hold a 1 lb weight (to start with) in each hand while in the water. First hold them close to you body and see if you still rotate vertically (you probably will), then gradually extend your arms to see if that allows you to remain horizontal. If you have to switch to holding a 2 lb weight in each hand (again, taking weight out of the pouches), do so until you find a point where you can remain horizontal.

When I keep my legs straight, they sink and I'm in a head up position. If I pull my legs up so that they're in the cool-cave-diver-frog-kick-position (not that I've mastered the frog kick at all) my trim seems to be much better.

A good example of the effect of changing the ‘moment’ of your weight placement. The weight of legs and feet are the same, but this technique shortens the ‘arm’ – the distance between the CG and the weight, and therefore reduces the moment. Plus, developing a frog kick as the primary propulsion technique is something more divers should do.

 

[james croft]

I also think overweighting is the culprit for most of these problems.

 

[Interceptor121]

Assuming you are not over-weighted you can try putting some of the lead on the cylinder strap and move the tank upwards one hand, so you don't waste money buying trim pockets if that does not help

 

[Rick Inman]

I have experienced and witnessed that sometimes a diver will focus so much on moving and shifting and adjusting gear that they forget to work on technique. Yeah, you should start by being correctly weighted (not over-weighted). But even then, you might find that doesn't solve it all.

You can create a lot of trim adjustments just using your arms and legs. If a diver is in perfect trim and they bring their arms in, they will go head down. If they bring their feet in they will go feet down. Spreading the fins apart (or the hands) can stabilize side to side. With 2 hands and two feet that can adjust in any direction, the various combinations of positions can allow a multitude of adjustment. And then a little shifting of gas in the drysuit into the feet, or up toward the head. And it doesn't take much. Many divers are making these subtle adjustments constantly without even knowing it - bringing their fin tips up just a bit, the hands forward a couple of inches, etc. Which is why an experienced diver could have a couple of pounds of weight tossed here or there randomly on their kit and at first, though it might take some effort, they can still retain their trim. Experienced divers will maintain good trim with an AL80 stage or two that's full at the start of the dive, and then empty at the end, even though there are several pounds of change in weighting placement.

IMHO, most of the trim issues (once the basics of weighting are corrected) resolve themselves after some time in the water. It's amazing what 50 dives will do. I'd bet we could hide 5#'s in NWGratefulDivers left DS pocket, and although he wouldn't like it, if you dived with him I'd bet his trim would still be spot on.

 

[SparticleBrane]

Rick wins this thread.

 

[dkktsunami]

I also think overweighting is the culprit for most of these problems.

Two different subjects. A diver can become neutrally buoyant while being grossly overweighted merely by putting air in bc. A properly weighted diver can have terrible trim depending on the placement of movable weight. Finding the proper weight, first, by a buoyancy check at 10' with 500 psi, is step one. Then, as mentioned above, diver should attempt to remain completely stationary and see which end sinks (head or feet). If diver remains level all is good.

 

[GrumpyOldGuy]

I have always found proper weight and trim a moving target. It changes as your skill increase, it changes during the course of the dive, it changes as you gear ages, it changes when you add new gear, etc...

I found a clip on weight of some type to be a valuable tool. It can be an old ankle weight or a small conventional weight with a clip attached. You can move it around and compare dive to dive if different locations are better before messing with other options. This is a better comparison than a static check and the begining or end of your dive. Also, at the end of the dive, you can pass it to your buddy and see if you can drop another pound at your safety stop (which is really the gating factor for the minumum amount of weight you need).

 

[Jeff Toorish]

Some great comments here.

When you go into a hover position, and your feet start to drop and your head comes up there are probably several factors contributing.

As Pete said, your tank may not be in the best position. If you like where your tank rides, consider putting an ankle weight (or even two) around the valve at the top to balance it.

If you are wearing a weight belt, constantly fighting an upright position is often an indicator of too much weight on the belt. It can also mean your belt is riding too low. First try trimming the belt higher on your waist (and making sure it does not ride down during the dive). Then start removing weight to see if that helps.

Going into a vertical position can also mean you are using a BCD that is too large and air is getting trapped in the bladder. That air will eventually move up in the BC and start to pull you into a vertical position.

Very heavy fins can add to the problem but normally won't cause it.

If you are carrying a lot of gear on D-rings or in pockets that are riding low on your body, that can also contribute to the problem.

Jeff

 

[Jasonmh]

...You can create a lot of trim adjustments just using your arms and legs. If a diver is in perfect trim and they bring their arms in, they will go head down. If they bring their feet in they will go feet down...

Hi Rick,

I may not be reading this right, but it is the opposite of what I have experienced. If I bring my feet "in" (as in pull them towards my butt), more weight is shifted forward, causing me to go slightly head down. If I extend my legs (away from my butt), then I have shifted more weight to the back and will go slightly head up. Is that what you meant to say, or did I read it wrong? Thanks.