Floating coastal structures offer viable alternatives to land reclamation as global populations increase, particularly in land-scarce cities such as Hong Kong. Steel, known for its high strength and low weight, has been extensively utilized in long-span structures on land. However, its use in marine environments is restricted due to poor corrosion resistance. Concrete, specifically grades of C60 or higher, has provided a more durable solution for pontoons but still poses challenges in self-weight reduction. This paper introduces a novel floating pontoon combining ultra-high-performance concrete (UHPC) with a steel skeleton. The corrosion resistance of UHPC effectively protects the internal steel structure with a lower self-weight of pontoon unit can be achieved. Shell and beam-column elements are utilized to numerically simulate the proposed pontoon unit. An advanced second-order analysis by employing the constant load Newton–Raphson method is used. Finally, the section capacity analysis of the steel skeleton and stress analysis of the UHPC panels are subsequently presented.