If you're a hardcore fan of all things maritime, you'll probably enjoy this sea-salty museum. Its sprawling collection includes historic lighthouse parts, navigational instruments, model ships and the odd ship-cabin replica. The real highlight is the gigantic HMAS Diamantina, a restored WWII frigate that you can clamber aboard and explore.
The museum is located beside Goodwill Bridge, at the southern edge of South Bank Parklands.