A wide, empty beach at low tide under a clear blue sky

A snapshot of the surface, ready to save

Fold it into a boat

valley fold mountain fold
  1. Cut the square
  2. Valley-fold both midlines
  3. Mountain-fold both diagonals
  4. Collapse into the base
  5. Fold the sides up, front and back
  6. Open the base, pull the ends apart
  7. Flatten the hull — it floats