This part was mostly about finding a sensible way to transfer the animation of the sails into the game from Blender. 

What I ended up doing is writing a more or less general purpose object which attaches game objects to armature bones (the armature animation is exported from Blender). It's nothing revolutionary, but armature related code gets pretty involved with its many coordinate systems to keep track of.

This will be reused for animating the steam engine, so that should be pretty quick to set up.