About five minutes. These resorts are part of the Epcot resort area which consists of the Beach Club, Yacht Club, Boardwalk, Swan and Dolphin.
The two furthest away are the Beach Club and Boardwalk and that is only about a ten minute walk.
They are all located around Crescent Lake. The Yacht and Beach Clubs are on one side. The Boardwalk is on the other side. The Swan and Dolphin are kind of between the two off to the side.
Great area to eat with a lot of great restaurants. You can walk to the Epcot International Gateway from any of these resorts in just a few minutes. You can also walk to the Disney Studios in maybe 10-15 minutes from the closest (Swan/Dolphin/Boardwalk).
The Friendship boats serve this area. They run between the Epcot IG and the Disney Studios making three stops at the Epcot resorts along the route.