ok. but i'm not sure that if you want to hang out in town every night, up north is for you. we did, at journey's end. it was 15-20 minutes on a speed boat to get to town, and $5 US PER PERSON each way. some resorts have gratis ones 2x a day, but probably not at 2 AM. and bring a hat with a tie if you don't like the "flock-of-seagulls" look.
i think the water taxi's stop around midnite, but i do not know how reliable they are. you may need to make sure they know you will be coming back late.