Due to the economy Disney no longer has funding for the boats to and from the Fort. You have to go the the Bike Barn and rent a canoe to get to the MK. The buses will still be operating for a few more days until GM files bankruptcy. Then the bus transporation will discontinue. A sign of the times I am afraid.
Honestly, as you can tell. I have no idea when the boat leaves for the MK but I am sure someone will let you know soon.