Porte designed the F.3, a slightly enlarged variant of the F.2, which was put into production. The F.3 soon proved to be inferior in many respects to the F.2, but by the time this was realized full-scale pro-duction was well under way and could not be halted. This accent on F.3 production inad-vertently prevented full importance being given to Porte's final biplane flying boat design, the F.5.

Span: 31 m (102 ft) (upper), 22.6 m (74 ft 2 in) (lower)

Length: 15 m (49 ft 3in)

Height: 5.7 m (18 ft 8 in)

Maximum speed: 150 km/h (93 mph) at 609.5 m (2000 ft).