Customs is responsible for providing a civil maritime surveillance and response service to a range of government agencies. Customs Coastwatch, a division of the Australian Customs Service, provides this service. Coastwatch uses a combination of assets in order to manage and coordinate this responsibility. This includes contracted aircraft, seagoing vessels of the Customs National Marine Unit and Australian Defence Force patrol boats and aircraft. The activities of Coastwatch are determined by the surveillance and response needs of the various government agencies that form its client base. Coastwatch vessels patrol the Australian coastline, Australia’s offshore territories, the Australian Fishing Zone and the Exclusive Economic Zone surrounding these areas. Australia’s offshore maritime area amounts to approximately 37,000km of coastline and an offshore maritime area of over nine million square kilometres. Increasingly, Coastwatch is being called on to investigate incidents beyond the Exclusive Economic Zone. Coastwatch plays an important role in supporting Australia’s Oceans Policy by identifying and responding to illegal fishing in Australian waters. Coastwatch detects and reports environmental incidents such as marine pollution and contributes to marine species protection through reporting sightings of marine animals. Coastwatch also provides support to Australia’s search and rescue authorities. Surveillance flights are undertaken to detect and report activities as diverse as people smuggling, attempts to import or export prohibited goods, illegal trafficking in flora and fauna and human incursions on coral reefs and other protected areas. These represent potential threats to quarantine, health and marine habitat. The key to Coastwatch’s effectiveness is an operational method that is client-driven, threat-based and risk assessed. Coastwatch’s effectiveness is directly related to the quality and timeliness of available information and the intelligence assessments that are derived from this information.