Actually, verlets are pretty well suied for buoys/boats. Id wouldn't be hard to write a little verlet physics, add a loop that checks if verlet's under water, and move upwards. People keep on thinking that verlet calculations are expensive. Halos' demos are slow because he made a really bad implementation of constraints, creating and freeing temporary pivots for EACH constraint, and then Using blitz rotation/pointing/movement commands to correct. Oh well. A bouy could be 1 particle.3 particles, or four. Depends on how much you want it to do. It would be good for boats, cause it would have realistic collision with land instead of blitz entity collisions. With alot more work, you coud get boat-boat working.