Great Brittain ordered 106 units of PBY-5 (dubbed Catalina I), while England ordered 200 units of PBY-5 (which were later officially named Catalina as well).
The main differences between PBY-5 and its predecessors included a higher power engine Pratt & Whitney R-1830-82, operating on 1200 hp, a redesigned tail unit and replacing flat windows with waist gun blisters. The PBY was used as a bomber and torpedo carrier, and was often utilized in night operations, as well as on patrol, rescue and transportation missions.
PBY Catalina was the most massive of the hydroplanes. Out of 3300 planes spanning all modifications, more than 100 are operational to this day, redesigned for civil purposes.