My watch looks like it has moisture in it and it stopped working.?

I have had this Casio watch for a long time. I bought it while I was in Kuwait in the Middle East. I love this watch, and it is hard to find a decent watch to replace it. It is 200m water proof. But recently I noticed moisture in it ( I can barely see the hands), and it stopped ticking today. It ticks when I smack it with my palm of my hand, but stops after a few seconds. Is there anything I can do to fix it, or is it time for me to buy a new watch?