The document provides information on the Boeing P-8 Poseidon, a military aircraft developed for anti-submarine warfare and maritime surveillance missions. It was developed by modifying the Boeing 737-800ERX to carry weapons and deploy sonobuoys. The P-8 replaces the older Lockheed P-3 Orion and entered service with the US Navy in 2013. Variants include the P-8A for the US, P-8I for India, and a proposed signals intelligence version. The P-8 has a strengthened fuselage and wings compared to the 737, along with enhanced sensors and weapons capacity.