Port or Starboard..?

These are the boats which are used to transport barrels of Port from one side of the Douro river to the other-Oporto is the home of Port and there must be 20 or so producers -famous brands like Sandeman, Cockburn, Carr, Dow, Ferreia.... ! We had a small tasting session and tried some great dry white port and a delicious rosé -both very tasty with olives and chocolate!!