There has been a lively debate of late, about a sand yacht that has
demonstrated speeds downwind
of about twice the windspeed - sustained.
People who have been notable for talking about its impossibility, its
contra-physics aspect, perpetual motion,
etc in this connection, have reported themselves as having a physics
background.
It's that old physics attitude thing, I fear.
uTube has quite a few clips on full size and toy size devices of this kind.