The Indian Navy contracted for eight P-8Is with the US Government in January 2009 at a total contract price of $2.1-billion, and is concluding paperwork to exercise options for four more aircraft. Boeing believes the Indian Navy may require a fleet of 30 aircraft to fulfil its maritime surveillance requirements on the platform. Two critical pieces of hardware on the P-8I absent on the base P-8A Poseidon for the US Navy are an aft-radar and magnetic anomaly detector to detect sub-surface activity.