You can choose one of these options for either Saturday or Sunday:

Free Tickets to the North Carolina Aquarium at Ft Fisher, a 30 minute ferry ride across the Cape Fear river.  Money for the Ft Fisher Ferry ticket from the Southport Ferry Terminal is also included  

Two hour boat ride from the St. James Marina with an OAE volunteer Skipper  

Miniature Golf on Oak Island

Regardless, whether you choose an amenity or on your own, the beach facilities and other amenities are available until dusk.