Okay, so I walk faster than most, but the trip from IoA to the RP can be made in 7 minutes. It took 12 to go from inside the movie theater to our hotel room (but we were back in time for the O.C.). If you are not exhausted, I would definitely say that walking is faster than riding the boat since you have to wait to board, take the actual ride, unload, wait for the next boat, ride, and then unload again. Walking would be so much faster getting there. Going back, take your time and take the boat. That way you will get the best of both worlds.