Especially on the midstream row, things can get exciting when the tidal flow is from astern and then there is a big wake superimposed on that situation.
Some years ago we were on the last upstream piles, facing downstream, outer row, and had a standing wave form that would break into the cockpit
when a ferry
would go by during max ebb. Left the piles and anchored just upstream from them... if hadn't been aboard when it started it might have been a real mess!