The Watanabe K6W1 Experimental 11-Shi Intermediate Seaplane Trainer was a failed design for an aircraft to replace the Yokosuka K5Y Type 93 Intermediate Seaplane Trainer.
In February 1936 the Japanese Navy asked Kawanishi and Watanabe, the two companies that had been building the K5Y, were asked to produces designs for a replacement aircraft. This has the designation 11-Shi Intermediate Seaplane Trainer and was to use a Kotobuki engine.
Watanabe produced their design between April and October 1936. The first of three prototypes was completed by May 1937 and underwent Naval tests. The K6W1 was a single-engine single-bay twin-float biplane, with a metal structure and fabric covering. The crew of two (trainer and trainee) were carried in open cockpits.
In the end neither the Kawanishi nor Watanabe designs were judged to be acceptable. The K6W1 didn't handle as well as the earlier aircraft, and it behaved badly when landing or taking off. Watanabe made a series of attempts to improve the design, but these failed, and no further aircraft were built.
Engine: Nakajima Kotobuki 2-kai 1 or -kai 2 nine-cylinder air-cooled radial engine
Armament: One forward firing 7.7mm machine gun, one flexibly mounted dorsal 7.7mm machine gun
Bomb load: Two 66lb or four 22lb