The definitive 1913 Model F was used by the US Army as well as the US Navy, and sold to several civil owners and a number were exported. Of wooden construction, the two-bay biplane had inter-plane ailerons on each side, fabric-covered wings and tail unit, and a carefully contoured single-step plywood-covered hull which accommodated two side-by-side in a cockpit location just forward of the wings. Power was provided by a 56kW Curtiss O engine driving a pusher propeller, the engine being mounted on struts just below the upper wing centre-section.

The 1914 version of the Model F had rounded wingtips, a tougher hull and increased strut support for the engine to prevent it collapsing on the crew in the event of a crash. This basic design was ordered by the US Navy, and after the United States entered World War I on 6 April 1917 it was adapted as the service's standard primary training flying-boat, 144 more being ordered.

The 1917-18 version of the Model F eliminated the original shoulder-yoke type aileron control in favour of a more conventional arrangement; and some aircraft had the ailerons transferred to the upper wing from the interplane position, span of the upper wing being extended. Several ambulance conversions flew with provision for a stretcher patient to be carried above the hull behind the cockpit. The more powerful Curtiss OXX-3 engine was fitted from 1917 onwards.

The Model F, particularly in its earlier versions, was sold to a number of foreign navies. Russia obtained a considerable number for operation in the Baltic and Black Seas. The Italians also flew the Model F and eight examples were licence-built by the Zari company at Bovisio.