The DD Boat dock is as Chuck described. It is located just below the flag pole at the end of the portico between HH and Olivia's along the Turtle Krawl boardwalk.
In this photo, the dock for the boat to DD is on the left at the waterline. HH is the building on the left, Olivia's is in the center of the image, Community Hall is on the right. Just off the photo to the right is the main pool and the OKW lighthouse.
Enjoy!