RAWalker,
Thanks for the info. I was in the pool last week and when I took a deep breath... I sank under the water. However, I did not try to see if I would go to the bottom. I then put on a 3mm core warmer. I exhaled and again my head went under water. When I held my breath I was able to keep my head above the water.
I will be going back to the pool again tomorrow. I am going to try different ways of floating including head down "drown proof" and floating on my back.
Again, thanks for the info on floating. I will def give it a try.