Dragonfly, Grasshopper, Scorpion, Locust, and Mosquito were built as Japanese and Chinese developments increased pressure on Britain's Far East presence. At roughly 594 tons, the boats carried two 4-inch guns, a 3.7-inch howitzer, and machine guns. Their 4-inch mountings elevated only to 40 degrees, sharply limiting their value against aircraft. The design therefore made sense as a shallow-draft presence and river-work vessel, not as an armored combatant built to survive a fleet fight or sustained air attack.
Chapter · 34:34-36:29
Dragonfly class design and Far East role
The Dragonfly class appears as a late-1930s Royal Navy answer to Far East presence needs rather than as a true armored warfighting class.