Atlantis- Leaving on your own after Excursion

[Lilystar]

Hey! I have a question. We have been to Atlantis many times before, both as day excursions and also to stay there. We are going to be in Nassau on the Mariner of the Seas for a full day from 8:30am-9pm in October and buying the ships excursion to Atlantis is pretty much the same price as doing it directly through Atlantis. This is the full access to Aquaventure, pools etc. The only thing is it lists the excursion from 9am-2pm, which is kinda a short timeframe when we aren't sailing out until 9.  So I'm wondering if there is any reason that we can't take a taxi back later to the ship from Atlantis. Atlantis doesn't kick us out of the pools until they officially close them up right? I just wanted to be sure that the day pass wristbands aren't like kicked out at 2pm or something. Anyone have experience with this?