Travellers usually only visit the chaotic, traffic-clogged town of SEMPORNA because they plan to scuba dive and snorkel off nearby islands such as Sipadan, Mabul and Kapalai. While some divers base themselves on the islands, particularly Mabul, a backpacker scene has developed in Semporna since staying inexpensively can release funds for an extra dive or two. It also gives access to the more northerly islands, not usually visited from Mabul.

Semporna broadly consists of three sections: downtown, the commercial centre where buses and minivans stop; Semporna Seafront, home to dive operators (there are yet more out in the resorts themselves) and most tourist accommodation (plus an ATM in front of the Giant supermarket); and the jetty-lined Jalan Kastam, which holds more dive kiosks, a few cafés and the business-oriented Seafest Hotel.