I’m diving tomorrow in salt water. New set of steel HP100 tanks, that I’ve used in fresh and brackish (fresh/salt) water. I’ll use the calculator for an adjustment, and let you know how it turned out in a couple of days. Currently I use no weight with a skin, and the calculator says salt water will require 10lbs +or-. I think that is pretty close, as I was calculating about 8lbs minimum on my own. I cast my own weights so they are only about $1 a pound. May leave a couple of lbs on the bottom if necessary. (: