IcyWindAnother goalie of around a season and a half here. Try staring straight at the ball, nothing else. The minute you look at the shooter's eyes, you start following where he fakes. Try moving your arms in the water when you eggbeater up. That helped me keep from getting "stuck" when I didn't move my arms in time.
I might be giving awful advice, but it works for me.
i used to play goalie, moved on to swimming now but for me what worked was just complete prediction or, if you/they are at a low to mid skill level, its not that hard to follow when they are faking or shooting. cheers and gl, its a great sport