Would Black Cat Catalinas outperform Coastal Command?

Would US Black Cat PBY squadrons have mauled German U-boats more effectively than RAF Coastal Command?

Probably not; the Black Cats were capable, but Sunderlands offered a stronger combination of range, ordnance, radar, and armament for Europe.

The black-painted PBY Catalina squadrons are considered capable and potentially useful against U-boats. The comparison nevertheless favors the Sunderland for European operations because of its range, ordnance, radar, and heavy armament. The answer later returns to the Black Cats' effectiveness in their own theatre and stresses that the comparison depends on the date. Their development around 1943 is placed after the Sunderland had already become widespread. Transferring successful Pacific units would therefore add useful aircraft without automatically surpassing the force already operating over the Atlantic.