Though Scott Russell's barge wave observation is noted there,
the more exciting (to me at least) observation is that TWO
drays starting a barge into fast movement will allow one to be cast off,
while the other dray continues to haul the heavy barge much faster than usual
while riding its soliton for miles.
For the purpose of this investigation not very applicable: there's not
usually room for two Mexican waves (or barges) traversing in opposite
directions in that canal system.