HELP: Bouancy/weight problems

I'm a relative newbie who "thought" I was doing well with my bouancy & weights until a recent trip to Bonaire. Now I'm totally confused & need some help. I have an Oceanic Isla BC with integrated weights. Used this while wearing a skin in Cozumel & Fla. last year and did well with 10# of weight. (I "know" I should be using less weight: BUT... I'm working on it!) Anyway earlier this month we went to Bonaire & I wore a 3mm rather than a skin. After my test dive I thought that I needed 14# (had 4# in each front pocket & 3# in each rear). Well to make a long story short: throughout most of the trip I found that I was tending to stay at an angle (/ head up, feet dangling) rather than horizontal. Didn't really know what this meant until someone told me that I was wieghted too heavily. Unfortunately this was on the next to last day of our trip. Next day I was advised to try dropping to 10# with my weights distributed 3/2 2/3. My bouancy check went well and I found that I was floating much more comfortably and horizontally until I reached 1000 on my tank. Then inspite of venting my BC (Which I routinely do as my air decreases) I was fighting to stay down (and losing the fight). So on the next dive I tried 12#: we were on a boat & didn't have many weight options so I used 3/3 4/2. During this dive I found that I was once again swimming at a slight slant - "and" @ 1000 I was once again having a little trouble staying down. SO..... was I too heavy or too light???? Unfortunaely I wasn't able to make any more dives after that. What would be the best way for me to distribute my wieghts to avoid this heads up positionong? Would a weight belt be better??
I do plan to take a bouancy class - but suggestions would be appreciated in the meantime.

raise your tank up some, so the center of gravity for your tank is higher.

you could also put some weight on the tank strap instead of in your pockets, once again to bring the center of gravity up some.

You have buoyancy and you have trim.First you need to get your weight so you are neutral at 10-15ft with about 500 psi in your tank.Once you do that you can work on your trim.

Now you need to move your weights around till you are in a horizontal trim.That can be done by moving your tank up or redistributing your weights higher up.You can add ankle weights or a tank weight to the top of your tank.

Thanks!! I'll keep working on it. More suggestions and pointers would definitely be appreciated ... please!

What lal7176 said.

dancingtortuga once bubbled...
Well to make a long story short: throughout most of the trip I found that I was tending to stay at an angle (/ head up, feet dangling) rather than horizontal. Didn't really know what this meant until someone told me that I was weighted too heavily..

Click to expand...

Someone told you wrong! If you are tending to stay at an angle your trim is off. It’s possible to be 20 pounds over weighted and have perfect trim.

dancingtortuga once bubbled...
Next day I was advised to try dropping to 10# with my weights distributed 3/2 2/3. My bouancy check went well and I found that I was floating much more comfortably and horizontally until I reached 1000 on my tank.

Click to expand...

It is also possible to be trimmed correctly and be over or under weighted, in this case sounds like you were under weighted.

dancingtortuga once bubbled...
(I "know" I should be using less weight: BUT... I'm working on it!)

Click to expand...

Beyond being able to relax while your doing a weight check there’s not much to work on other than possibly reducing your percentage of body fat. Other than that your body’s natural buoyancy is what it is.

Buoyancy and trim are not directly related. However, the placement of the weight does effect trim. Here’s what I’ve learned from Uncle Pug, Mike F., and a host of others on the board.

Step-1 – Weighting – You should be neutrally buoyant with half a breath, just below the surface with no air in your BC and a near empty tank. Don’t worry about your orientation, head up, head down, horizontal, there’s all O.K. But, you need to be relaxed and stop moving, especially your fins. In my limited experience the ability to relax and stop moving is the biggest obstacle for new divers to overcome on the road to proper weighting.

Step-2 – Trim – Good trim is achieved by moving the weight you need around, either by where it’s placed or body position. With good trim you can effortlessly stay in any orientation head up, head down, or horizontal.

Based on your description it sounds like you are feet heavy when properly weighted. If so you need to somehow shift some of the weight higher. The easiest way to do this is to mount your tank higher in the BC. Another thing you might want to try is to get a pair of ankle weights, wrap them around your tank valve and remove an equal amount of weight from your weight belt.

Good luck,
Mike

They post above have it right. There are 2 different but related parts to your problem. First is actually being neutral. This needs to be determined first as described above. I do it at the surface rather than at 15 ft, there is a debate which is best, thats a personal call. The part about the tank being at 500psi is very important. If you just can't do a bouyancy check at 500psi then second best is do it with a full tank and add 5 lbs AFTER you find you correct weight (assuming you are using a 80 cf tank). The extra 5 lbs accounts for the weight of the air in the tank you will loose during the dive. You have already experienced this based on your post, sounds like you did a B check with a full tank.

" My bouancy check went well and I found that I was floating much more comfortably and horizontally until I reached 1000 on my tank. Then inspite of venting my BC (Which I routinely do as my air decreases) I was fighting to stay down (and losing the fight)"

You only added 2 more pounds on the second dive, you need about 5 to offset the loss of the air.

The next part is trim, head up/down. To accomplish the desired angle, you MOVE weights around (but keep the same amount)and/or adjust the position of your tank. If your BC has rear weight pockets and you want to really get particular with your trim, you can adjust the exact placement of the weights in the pockets. I have placed empty plastic Coke bottles with holes cut in the bottom (to prevent air trapping and cut to length) in the trim pockets of my BC and placed the rear weights on top of them to shift the weight upward in the BC which tends to put me in a more head down position. This is for very fine adjustments however.
Hope this helps, it takes some experimentation to get it right for you.

Good answers.

The mechanics are really pretty simple but almost nobody teaches it.

As you descend and the suit compresses you add air to the bc right? Now what do you have? You have a buoyant bc (upper half of your boddy) and a heavy waist (where your belt or pouches are). It should be no revelation then that the bc goes up and the feet go down. You need the weight where the buoyancy is. Of course the exact placement and amount will very depending on your equipment and the build of your body.

The people who say the head up attitude is caused by too much weight have done too much reading and not enough thinking. The more weight you have in the wrong place the worse the problem but the problem stems from having the weight in the wrong place.

Boddy position will also effect trim but you can't even work on boddy position until you get your balance close to where it needs to be. As boddy position improves you may need to make further adjustments.

Good luck.

THANK YOU!! Makes alot of sense. SO much to learn - So great to have this board to help me do so. Can't wait to dive again & put these suggestions to the test!!

Hi,

I don't know if the Oceanic has them, but some BCs have weight pockets (non-ditchable) that sit behind the divers shoulders.

Look between the back pad and the air blader up near the top of the BC.

If they are there, put smaller weights in the 'main' waist ditchable pouches and add 1 or 2 pounds in each shoulder pocket.

If your BC doesn't have the pockets, I'd experiment with the ankle weight at the top of the tank ideas as mentioned above.