Developed from the single seat Blackburn Dart, the two seat Velos was built against a contract from the Greek Navy who had a requirement for a coastal defense sea plane. Flying for the first time from Brough Aerodrome in 1925, the first four were produced and sent to Greece where a production line had been set up to produce a further 12 at the Greek National Aircraft Factory. These differed in having a raised rear cockpit to give the gunner a better view and a deeper radiator. A total of 22 were produced with four going to the North Sea Aeriel and General Transport Company (the Blackburn Reserve School) where they replaced the earlier Dart and were themselves replaced by the later Ripons and Baffins in 1933.