Yeah I know about the problem but I honestly can't think of an easy solution (the Vertex shader of the water can't communicate with any c# scripts), but thank you to pointing it out (;
Kobliznik I think I have the solution to your problem.
And then make it so that the circle and thing above will shrink and expand depending on if the player moves forward or backward, and if the player moves the camera up down left right, make it move the opposite way by using camera position or whatever.
You will also have to account for random player position upon start of fish fight so the circle is in the right place and the right size. im believe you can figure it out but if you are having trouble holler. I don't remember if the boat bobs, but if it does, take that into account too.
P.S. if that somehow works, can you credit me in the credits?
I'd say it would be decently hard to do because this possibly has never been done before, so don't be pressured to do it.