When the dober is going under water. And what the other guys are saying; when you see your bars lift half way, it's a good time to strike and indeed also use R3 up or sideways when you strike with R2. Just be patient, wait till the fish bites good and you'll have him almost everytime! Watching some youtube videos of real fishers helped me a lot in this game and I also watched some vid's about lures, so there's a tip have fun and good like