shrswnm:But nobody answered my original question: does relative muscle mass make a difference for floaty legs? It seems to me it might as muscle weighs more than fat. Am I thinking correctly?
In my experience, floaty ankles is more prevalant in the fairer sex... I don't have any opinion as to whether it's a physiological difference or something else, but certainly more muscle and less fat in the legs would have an effect. Most people I train who suffer from floaty ankles struggle with the fin pivots in shallow water and I resort to ankle weights to help them in the pool. Generally in deeper water, 10-12m where these people manage the skill admirably without ankle weights. It's certainly no barrier to getting out and doing some great dives.
The advice you've been given, such as shifting your tank lower on your back will help you come to terms with your ankles!!
Having quickly trawled through the thread, I have to agree with Walter in that I believe that ankle weights are unnecessary for everybody, but it does take training and practice. It's basically personal choice whether someone wants to use them or not...... heck, I wish someone would invent ankle floats a I've got the most dense ankles in the world and struggle to stay in trim when diving wet....!
For the ankle weight devotees, what would you do if you lost ankle weights during a dive? Probably more relevant to drysuit divers who use ankle weights to overcome too much air in the feet... I only ask, as when it's my turn to clean the pool I always end up pulling out a fair amount of lead shot from the bottom where peoples ankle weights are leaking....!