Today, air-to-surface vessel (ASV) radars, or more generally maritime surveillance radars, are installed on maritime reconnaissance aircraft for long-range detection, tracking and classification of surface ships (ASuW—anti-surface warfare) and for hunting submarines (ASW—anti-submarine warfare). Such radars were first developed in the UK during WWII as part of the response to the threat to shipping from German U-Boats. This book describes the ASV radars developed in the UK after WWII (1946–2000) and used by the RAF for long-range maritime surveillance.