The Boeing P-8 Poseidon is the US Navy’s advanced maritime patrol and reconnaissance aircraft, providing anti-submarine, anti-surface, and ISR capabilities. The aircraft first entered service in 2013 and has replaced many of the aging P-3 Orion fleets of maritime patrol aircraft. While the Boeing P-8 Poseidon has proven the most popular maritime patrol aircraft in the world, it is not the world’s only maritime patrol aircraft, with some countries like France making their own counterparts. Here is what to know about the world’s current and future fleet of P-8 Poseidons.