The map to Paradise Island is located at the top-most level of the casino-boat near the steering wheel. The boat is at the dock that is at the bottom of the stairs in the ground of Glasstown. Additionally, once you pick the map up, leave the room. Return later, and it will be there again. It will always be there whenever you go back to that room. It is recommended that you not pick it up; there is no way to get rid of it after you have given one copy to Gordie Puck (in the university). It will be once less space in your pocket to carry something else.