FlySim

FlySim features full 3D graphics, accurate casting dynamics, and realistic fish behavior. FlySim's physics-based casting integrates everything from air resistance to water tension for ultra-realistic casting dynamics.

You can overhead cast, roll cast, mend, and shoot line with enough accuracy to learn the fundamentals. The fish use a sophisticated strike engine and physics-based movement for realistic striking and fighting behavior.
The full version offers nine destinations and ten species of trout. Version 1.5 added 3 new destinations and several new species of fish. The demo users can now explore several of the new destinations, but they cannot fish in them.