I've managed to implement nice bow and stern waves. They should satisfy everyone. I will introduce them at the beginning of February in the next beta release. I'm preparing the 2.0 branch to be released as stable. I'm removing unsuccessful experiments and work on final implementations of everything. This functionality is restricted to the beta releases for the time being. I will publish it soon on a different host. Sorry about that I think that Chucky and Sub Vol may be the cause. They don't have a Rigidbody and thus are used by the boat as a part of its collider. Try to add a Rigidbody to them, set their mass to 0.001 and set them to be kinematic. There seems to be a way to do this without raymarching. I'm working on this. I'm not sure how far I can go with caustics in forward render mode. It would require to use a custom shader on each affected object (to get a correct look) or it would work by simple brightening of affected pixels. I will give it a try.