Model Variants (Including Prototypes)
XOS2U-1 - Prototype Model Designation; fitted with Pratt & Whitney R-985-4 Wasp Junior radial piston engine at 450hp.
OS2U-1 - Initial Production Model Designation; fitted with R-985-48 engine; 54 examples produced.
OS2U-2 - Fitted with R-985-50 engine; 158 examples produced.
OS2U-3 - Production Variant appearing in quantity; fitted with R-985-An02 engine; increased fuel capacity and operational range; improved armor protection for crew cabin; 1,006 examples produced; self-sealing fuel tanks; provision for 2 x depth charges.
OS2U-4 - Proposed Improved Model with revised tailplane, wings, flaps and more powerful engine; never produced.
OS2N-1 - Based on the OS2U but production undertaken with the Naval Aircraft Factory.
Kingfisher Mk I - British Fleet Air Arm Designation for the OS2U-3 model series selected by 1941; seen in trainer and catapult launched scout forms.