- B-6 Shark Mk. II: Updated Tiger VI engine
- B-6 Shark Mk. IIa: Version made for Portuguese Navy with Tiger VIC engine
- B-6 Shark Mk. III: Updated 800 hp Bristol Pegasus III engine
The B-6 began as a private venture by Blackburn, which was intended to meet Specification S.15/33.It was based on the M.1/30A prototype. The B-6 prototype first flew on 24th February 1933 at Brough. The aircraft was then flown to the Aircraft and Armament Experimental Establishment at Martelsham Heath. After successful test landings on HMS Courageous,16 were ordered for The Fleet Air Arm in August 1934.
The prototype was later fitted with floats at Brough in April 1935. The first batch of Sharks went to 820 squadron onboard HMS Courageous. Between 1935 and 1937 a further 95 Shark IIIs were delivered to the RN. Eventually they were replaced in frontline service by Fairey Swordfish. They saw service in World War Two as target tugs and in Coastal Defence with the Portuguese Navy. Canada purchased seven Mark IIs and built seventeen Mark IIIs under licence.