The Uskok class was a class of two motor torpedo boats built for the Royal Yugoslav Navy (Serbo-Croatian: Kraljevska mornarica; KM) during the late 1920s. Named Uskok and Četnik, the boats were built by the Thornycroft Company based on their existing class of 17-metre-long (55 ft) Coastal Motor Boats, but were almost 1.5 metres (5 ft) longer. As their main armament they were equipped with cradles that carried two British-designed 456-millimetre (18 in) torpedoes, were fitted with hydrophones, and could carry depth charges instead of torpedoes if used in an anti-submarine role. The boats were lightly-built using mahogany, powered by two petrol engines, but lacked transverse bulkheads within the hull to mitigate leaks.