That wouldn't surprise me... in freshwater with a steel 72 on an aluminum plate and 3mm wetsuit I can get away with no lead but use 2 lb for trim on the top tank strap. My steel is denser than an AL 80, but my 3mm suit offsets that..... long story short, with a BPW in freshwater and a swimsuit, I'd be surprised if you need more than a few pounds (but I've seen exceptions at both ends of the spectrum!).So it looks like I may not need any lead if I'm figuring this all correctly, at least as a starting point.