If you are going to be in Epcot that day you can easily walk from the International Gateway of Epcot to the boardwalk area in about 10 minutes. The Friendship boats also run between the IG and the Studios all day stopping at the Beach/Yacht Clubs, Boardwalk, and Swan/Dolphin.
As someone noted, you can also walk or boat to the boardwalk area from the Studios but it is longer than from Epcot.