No matter what way you look at it, you'll need to switch buses a couple of times. One way is to take a FW bus to the TTC, switch to a bus for DTD, then get the bus to the Boardwalk.
It's about a 20 minute boat ride. It depends on whether or not the boat stops at other resorts on the way. It's a nice place to sit back, relax, and enjoy the sunshine and being at WDW!!