There are water taxis you can hire, if you are going to be out really late, I would try to arrange it ahead of time and ask where to find them, just in case they decide to go home and go to bed, which I've seen happen. When I worked at Journey's End I had guests call me and wake me up about 2:30 am one morning, they had gone to San Pedro to party and couldn't find a ride back to the resort. They wanted me to get out of bed, go find our boat captain, wake him up and have him fuel and drive the boat down to pick them up. Guess what I told them? They may still be looking for that ride back to the resort...