The aircraft's sensors are primarily intended for anti-submarine warfare (ASW) work but are also capable of maritime surveillance, counter-drug and search-and-rescue missions.

The CP-140 is Canada's only strategic Intelligence Surveillance and Reconnaissance (ISR) aircraft, conducting long range missions over land, water and littoral areas.

Work includes upgrading computer, navigation, communication and radar systems as well as making structural improvements to ten of eighteen aircraft.

Block II brought a glass cockpit with the Navigation and Flight Instruments (NFI) component provided by CMC Electronics,[5] and a complete replacement of the communications suite.

[6] The Aurora was acquired in the early 1980s to replace the CP-107 Argus and to further support Canada's anti-submarine warfare mission obligations under NATO for the northwest Atlantic sector.

[7] Short deployments to Alaska (Adak), Hawaii (Kaneohe Bay), Iceland (Keflavik), the UK (St Mawgan and Kinloss), and Norway (Andoya) were the norm.

Increasingly, as the CP-140 moves into the 21st century, it is employed for domestic and international surveillance by CANCOM for security, counter-terrorism and smuggling, as well as to monitor foreign fishing fleets off Canada's coasts.

[12] In June 2022 it was reported that Chinese jets had repeatedly intercepted the Aurora in a manner which the Canada military said failed to adhere to international air safety norms.

[15] Canadian government officials said the incidents were happening with increasing frequency and that they had lodged protests on multiple occasions with their Chinese counterparts, although an article by Global News said that China is not believed to have responded to the reprimands as the interceptions had not stopped continuing.

[19] Lacking the expensive, heavy and sensitive anti-submarine warfare as well as the anti-surface warfare fittings of the CP-140 Aurora, the Arcturus was more fuel efficient and was used for crew training duties (such as touch-and-go landing practice), general maritime surface reconnaissance (detecting drug operations, smuggling of illegal immigrants, fisheries protection patrols, pollution monitoring, etc.

[25] On March 28, 2023, the Government of Canada sent a Letter of Request to the US's Foreign Military Sales program to approve the purchase sixteen P-8A to replace the current CP-140 fleet, but it did not indicate any timeline for delivery.

[27] On November 30, 2023, Minister of National Defence Bill Blair announced the acquisition of sixteen P-8A Poseidon aircraft for the Royal Canadian Air Force.