Are you using a floatant?
If you get a fish, after releasing the fish make sure you wash the fly thoroughly in the water before drying it off. I find that blowing onto the fly hard a few times gets it pretty dry.
Then apply some floatant (not too much - just enough to help the fly stick in the surface film) and allow it to 'dry ' and you're all set.
When sight fishing, look over your shoulder from time to time, you never know who's behind you