The Darwin Beer Can Regatta is exactly the kind of event that makes sense in the Top End: inventive, informal, beach-based, and a little absurd. Held in the dry season, it centres on boats made from beer cans and other improvised materials racing off Mindil Beach.
It is only useful if your dates line up, but if they do, it gives you a very local Darwin day out. Expect crowds, sun, fundraising energy, and a sense of humour; bring water, shade, and no expectation that everything will run like a polished sporting event.