A tip that ive kinda learned at Deep Lake...

If your bobber is all of a sudden underneath the water, its a rainbow. No question. It is a 99% chance that it is a rainbow. I've had about 1, maybe two kokes grab it that fast.

With kokes, they tend to sit there and just play with it for awhile. thats why I only use half a worm at most, and a tiny piece of powerbait. use to much, and they will play with it FOR EVER.

When they finally take it, I'd suggest waiting for the bobber to be underwater. Even if they take off with it, I still like to wait for it to go underwater before i set the hook, mostly for reassurance.

If your bobber just tilts over and all of a sudden just lays on its side.. You can either wait and hope the koke isnt jetting it to the surface, or you can reel it in as fast as you can, and when you feel any pressure, set the hook lightly and see if you got him. It's a 50/50 chance hes going to jump if you see your bobber set over.