This is how it works. Choose a nice picture post card.
Address it to another boater on the system. Write them a little note of good wishes.
Put the card in a see through plastic bag.
(Self seal sandwich type works best.)
Put it inside the bag and also put inside this note........

"DEAR BOATER PLEASE PASS ON THIS CANAL POST TO ANOTHER BOATER
WHO CAN HELP IT REACH ITS DESTINATION."
INCLUDE IN THE BAG A FEW WORDS ABOUT WHO YOU ARE,
YOUR BOAT AND HOW FAR YOU CARRIED THE POST.
CANAL POST IS THAT SIMPLE!