Today, air-to-surface vessel ASV radars, or more generally airborne 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 and used by RAF Coastal Command during WWII for long-range maritime surveillance.