Upside Down Diver!

[h2ofria]

I have a weighty diving issue. Whenever I am hovering I gradually end up head down/fins up. Neutral bouyancy is not the issue, I can maintain the proper depth but every few minutes I have to do a tuck and roll to get back to the heads up position. This even occurs if I am relaxed while holding onto a mooring line.

I wear a Sherwood AVID BC with integrated weights, usually 12 to 14 pounds in warm saltwater. My fins are Mares and are slightly negatively bouyant. I wear a 3 Mil wetsuit in warm water. I am a male, 5 feet 10 inches tall and weigh 185 pounds. I usually use an 80 aluminum tank.

I tried using 1 pound ankle weights which helped a little and tried shifting my back weights to the front pockets, to get them lower on my body, with no effect.

Obviously I am top heavy. Anybody have any advice on how I can straighten up and fly right without so much weight on my ankles that I am constantly dragging the bottom.

 

[drdaddy]

H2ofria,

Does this happen with you with whatever exposure suit you dive with? From the information you have given, it's hard to figure out what is going on. Maybe someone here on ScubaBoard will be able to advise you, but it might be best to have someone along with you while you are diving to help you figure it out.

I am not an instructor, but I would be glad to help you figure this out in the cold murky waters of the Pacific NW. But you need to have/rent (Salem Scuba) a 7mm wetsuit (which would change your configuration).

I live in Corvallis, Oregon. I am going diving tomorrow morning (Saturday, February 7th, 2009) to Yaquina Bay, Newport - South Jetty. We have to leave Corvallis (my house) at 7:00 am.

We could work on this issue together. I have many different assortments of weights and it would be fine with me to help you. If you are interested, PM me with your phone number and we'll connect. Others would be welcome to come along.

If you can't get here/Corvallis for a dive tomorrow -PM me anyway and we can buddy some other time.

drdaddy

 

[Nemrod]

Wing and back plate. N

 

[h2ofria]

Thanks for the response. I did take a dry suit class and dove in Hoods Canal, cold saltwater. With 30+ pounds of weights I don't recall that it was a problem maybe because I had to use a weight belt in addition to my integrated weights.

I know that in the pool classes for dry suit I was constantly going toes up as I got used to the way the dry suit handled the air.

Thanks for the offer to go to Yaquina. My Hoods Canal experience pretty much convinced me that I was not a cold water diver.

I am up for warm water trips though - going to Belize, Hawaii and Little Cayman this year. The Belize and Little Cayman trips still have openings I believe. I will PM you with details if you arte interested.

 

[mudhole]

Think of the problem not as a piece of gear and what brand. . . but as an old-time scale, like in the scale of justice statue. The goal is equal weight on each side of the scale. The center of gravity moves up or down your body. If your tank rides high on your shoulders, then you must move your weight belt lower on your hips. If your tank rides low on your back, then the weight belt may be higher on your waist. Throw into this balance is where is the bubble of air you're putting into your BC.

Why did I talk about weight belt when you're describing weight pockets? Because, until you adjust gear to find your "center of gravity" weight belts give you some control. You could put more weight into the pockets and swim with a bigger bubble in your BC, but that invites more problems in the future. Just start with the simple placement of Tank, weight belt to get it right, then move weights to pocket, or what ever combination will keep you on an even keel.

 

[Bubbletrubble]

I wear a Sherwood AVID BC with integrated weights, usually 12 to 14 pounds in warm saltwater. My fins are Mares and are slightly negatively bouyant. I wear a 3 Mil wetsuit in warm water. I am a male, 5 feet 10 inches tall and weigh 185 pounds. I usually use an 80 aluminum tank.

I tried using 1 pound ankle weights which helped a little and tried shifting my back weights to the front pockets, to get them lower on my body, with no effect.

@h2ofria: Two ideas that might help improve your trim:
1. Specifically how are you distributing your weights? You mentioned that you've tried shifting weight from the back trim weight pockets to the front pockets. Have you tried a configuration in which you have no weights in your trim pockets and all of your weight in the front pockets? In most cases, divers should only be adding weight to the back trim weight pockets if they're feet heavy. Some divers errantly think that one must put weight in the trim pockets...simply because they are there.
2. Have you tried moving the tank camband higher up on the tank (closer to the valve)? Another idea is to attach some trim weight to the lower tank camband (I believe your BC has two tank cambands). XS Scuba has some nice mountable weight pockets that work well on cambands.

As you know, ankle weights and/or more negatively buoyant fins should improve your trim. Also, how you position your feet relative to your body can affect your trim.

If all these adjustments fail to help, then I'm with Nemrod...get a BP/W.

Mudhole gives good advice about trying to find your center of gravity. Trying to attain proper horizontal trim is like trying to balance a teeter-totter.

 

[muddiver]

Keep in mind that most men are top heavy without any equipment on. Thus using mudholes analogy you need to move the weight you are carrying, either up or down your body to trim yourself out.

I switched to a weight system (pouches on a belt with suspenders) by DUI to allow the adjustment. Usually I carry my weights at my hips, or just below where most of us would wear a belt, and that ballances my trim. Ankle weights are good if you have floaty fins and I use them with my dry suit.

Moving weight from back to front does not change the location of your center of gravity in respect to your feet. It will just keep you from rolling from left to right and ending face up.

 

[AzAtty]

Before you get too upset about your trim, how "heads down" are you? Is your head only slightly lower than your fins, or are you standing upside down on your head? Do you have to tuck and roll because your torso is actually sinking, or is it because you feel that you're to far inclined? Since we're vertical creatures, we sometimes don't have an accurate perception of how inclined we are.

Video or pictures or even a buddy are invaluable resources to determine your trim in the water. If you determine that you actually sinking forward, then I agree with others that it's a weight positioning issue, and they've given some good tips on that issue.

Here's another thing to consider: at what point of the dive do you go head down? If it's happening toward the end of the dive and you have a single tank strap, it could be the butt of your tank floating up off your back and pushing your head down. I've seen that happen from time to time when the BCD doesn't fit well. In that case, moving the tank strap toward the middle of the tank and adjusting the BCD will reduce the leverage the tank can exert against your torso.

 

[frozen newbie]

This seems like a valuable discussion. I decided to get a weight belt in addition to my weight integrated BC just because I have been wearing so much weight. I noticed that my trim was much better with the belt, now I know why, LOL.

 

[vlkr]

congratulations on picking that up naturally. it took me a lot of effort to be able to drift dive upside down.