LeeJP,

Your thread shows being from upstate NY. I am sure you are close to lakes and what not up there and therefore should be close to some Dive shops (SCUBA). Most of the threads have discussed goggles over masks. If masks are the way you want to go, I would suggest visiting a dive shop. Or, here are some tips to fit yourself with a good sealing mask:
Find the mask that you like and looks like it will fit your face well. Without using the strap, place the mask up against your face (make sure to move hair out of way). Inhale through your nose pulling the mask in towards your face then hold your breath. If you feel the mask pulling away, then you have air leaking in ( Not a good fit mask). Try this on several masks until you find the right one. You will know because that mask won't budge. I have a mask that I have had for the past 8 years for SCUBA diving. It still seals just as well since the first day I bought it. Good luck.