Hard to get horizontal

In preparation for my upcoming Christmas Fl Keys trip, I've been working on my bouyancy skills in an indoor pool. I'm 5'11", 190lbs, wearing a 3 mil shorty, my old sinking jet fins, and I have no problem descending with six lbs of lead on my belt. Problem is, my feet still sink, slowly, but nevertheless, they still sink.
So, in an effort to get horizontal, I managed to shift the weight fwd by slipping six 1lb lead ingots into the shoulder strap sleeves of my old Dacor bladder type BC. Pool isn't open today, so tomorrow after work I'm going to try this new method of weighting myself to see if I can attain a horizontal attitude.

Question is, about how much more lead am I going to need in the brine? Been a while since I dove in the ocean, and I don't remember how much lead I needed last time.
Tomorrow at the pool the plan is to see if I can get horizontal with both the six lbs on my shoulders, plus the six lbs already on my belt. And then I'm going to ditch the belt and empty the bladder and see what happens then.
Think 12lbs total is enough for a guy my size in salt water in a 3 mil shorty? Too much?Or if I can get horizontal with just the six lbs on my shoulders, how much more will I need in salt water? (I'm hoping I can just slip a couple more 1lb ingots in my bc pockets, and get by with a total of 8lbs without even wearing a belt).
And do floating fins make that much of a difference?

You'll probably need about six more pounds for the saltwater.

When I got a drysuit this spring I had to buy new fins since my old SP Jets wouldn't fit. I can tell you, the difference in trim between the Jets and my new OMS Slipstreams was quite dramatic. With the Jets I had to put weight up on my tank valve - you may want to try an ankle weight up there. With the Slips I had the opposite problem until I added spring straps - just that little bit of weight out on the end of your legs makes a big difference. FWIW, floaty feet make for a much more uncomfortable/tiring dive than sinking feet.

boat

When your feet sink, pull them toward your back by bending your knees and shift weight forward by moving your arms forward. Unlike a submarine, the human body can change shape, your ballasting concept is a little too unimaginative, you are thinking you are a submarine, but, actually you are a blob of protoplasm that can change shape to shift your center of gravity and your center of buoyancy. N

This is why I keep a log book with detailed notes as to exposure suit, weight needed, type of tank, etc. I for instance have not used my jacket bc in a drysuit with an al 80 in over 4 years. But if It were necessary to dive this configuration tomorrow I would put 4 lbs in each trim pocket, 6 in each integrated pocket, and 6 lbs in a weight belt and be more or less good to go with heavy undergarments. I might be able to shave a couple pounds due to experience but if not no big deal. It took me all of 3 minutes to determine this by looking back into my logbook.

That said, It sounds like you are modifying your bc to accept weights in a manner it was not designed for. May or may not work. I'm 5'7" 165 and use 8lbs in fresh water with a 3 mil full and 12 in salt with an al 80. Normally depending on the tank it is suggested to add 5 lbs for saltwater. The best way is to do a proper weight check when you get there. As for trim getting the weight over the largest air space is usually the first step for me with students. That means using trim pockets or a BPW set up. ALso getting away from a flutter or scissor kick and going to a modified frog where the knees are bent and feet up helps to change the center of gravity. Hand placement also helps. Look at some of the 5thdx videos on youtube for an excellent example.

http://www.youtube.com/watch?v=JlUjnXBzNlc

http://www.youtube.com/watch?v=oLcITiZYUdA&feature=related

http://www.youtube.com/watch?v=5xNfYI-Owb0&feature=related the correct way to demo mask clearing and perform it.

Not to start a debate on weighting/placement and gear selections, so I'm typing this as a matter of opinion. Try out a BP/W, or even a back inflate BC. Personally with a 3 mil shorty and a 6lb SS backplate I can stay negative in saltwater to around 250-300PSI w/ an AL80. Body position as already mentioned is also a very important factor.

If you want to really demonstrate to yourself what Nemrod is talking about, float on your back in the pool with just some light fins on (and your bathing suit) and move your arms straight out, then out to the side, etc, and move your legs straight out, then bend them up towards your back etc. Notice how you have to control your breathing at the same time to stay perfectly buoyant. It's very educational.

Thanks for the OMS Slipstream tip, boat. I never heard of those before. I always took it for granted that jet type fins were sinkers. That just might be my ticket. I put springs on my Jet Fins and that made them really sink.
But I have this new close up lens on my camera, so I plan on getting pretty close to the reef, and I'd like to be able to keep my fins off of it.

Yeah, I already watched some of those Youtube vids, and yesterday I did experiment with stretching my arms fwd and holding my legs bent, but that didn't change anything for me. I even held a couple 1lb weights out in front of me and my feet still sank.
I am considering a BP/W configuration, but that's gonna have to wait for now.

Sounds like you're compounding your original problem with the solution. Instead of moving weights around, try lighter fins first. The Slipstreams are a little stiffer but are *considerably* lighter. They are reasonably priced and if that solves your problem is saves moving weight around. Worst case scenario, you'll have some shiny new fins. )

I love my SlipStreams