Have a drink in the restaurant on top of Hyatt pier 66 and watch the Oasis sail at 5:30. Then remember that the following day people will be there watching you!
A lot depends on where you're staying. You can ride the water taxi all day for 20 dollars or after 5 for 10 bucks. There's a hop on hop off trolley, or you hotel may have a shuttle to the beach. We stayed at both the Embassy suites (free breakfast and cocktail reception filled with cruisers) and the Hilton Marina (free beach shuttle). Just walking around the Marina looking at the yachts was amazing.
It's also a good time to review what you've packed in case you've forgotten sunscreen, toothpaste etc. There are lots of great restaurants also. Bimini boatyard, Bubba Gump's, etc. Or subway, and a cold six-pack. The problem will be that you don't have a few more days to spend there.
Have a great time on the Allure. Be sure to have a roast beef sandwich at the Park Cafe on deck 8 and try Samba's Brazillian grill in the Solarium...unless you're a vegetarian.