I just might try them neck weights.... I have some little wieghts from a car tire company that are easy to put on a little belt or what ever I might come up with..
Crispin, I have not had the problem...yet, but I believe that I will when diving bit deeper than I have been diving..(-40--->) but I won't know till summer actually arrives to UK and Finalnd...
I gotta go......pool training

and one more silly question...how do you blow nice air-rings...mine usually brake into a small bubbles, but I have seen a rings that stay as one big circle almost till surface..
