US Company Boeing is successfully marketing and deploying the P-8 Poseidon patrol aircraft.
Major customers include:
- the US Navy - many delivered and on order. Some (like Patrol Suadron 45) operating or passing through Hawaii, Guam, Kadena-Okinawa and Singapore with major interest in Chinese (and probably Russian) submarine operations in the East and South China Sea. Also interested in conjunction with other allies (like India) in tracking Chinese submarines passing through the Straits of Malacca.
- Royal Australian Air Force - 8 on order with an option of 4 more. Some may be delivered in 2017. Australia may well buy some large Triton UAVs to work in conjunction with the P-8s.
- Indian Air Force - ordered 8 P-8I (I for India) called "Neptunes" (not to be confused with the old Neptune P-2s). All 8 P-8Is now delivered.
The US may have had some misgivings given India's close relationship with the Russian military. However weighed against this India's aims to use the (possibly lower spec) P-8Is to keep track of Chinese submarines and surface vessels would benefit US national interests against China.
India has one or two P-8Is patrolling the Andaman and Nicobar island area. India may be doing this in conjunction with US, Singaporean and (occasionally) Australian aircraft tracking Chinese submarines entering and leaving the Straits of Malacca area. For the ISR and possibly ASW mission Indian is also operating (Israeli built) Searcher-II UAVs in the Andamans/Nicobars. Also see an article in The Diplomat on Chinese submarines and India's Andaman and Nicobar Command.
- UK Royal Air Force - 9 ordered in November 2015. See Submarine Matters article.
- the Royal New Zealand Air Force may be a possible future customer for a few.
- Italy and Norway may be interested in buying or leasing P-8s.
It is often forgotten that ASW is only one of a P-3's or P-8's role. Safer anti-surface ship and overland ISR operations may be promoted through higher, faster flying.
The P-8 has major differences in structure and the way of functioning which takes some realising by many who are accustomed to P-3 Orions. The P-8 flies faster and higher than the P-3. Higher flight means less reliance on magnetic anomaly sensors and greater reliance on dropping sonobuoys. Higher faster flight means one P-8 can transit faster and arrive on station faster than a P-3. One P-8 can search more sea area faster than one P-3, so fewer P-8s may need to be acquired.
For overland ISR missions P-8 operation faster and higher contributes to safety against SAMs and small arms fire (eg. 14.5 mm AAA on peaks in mountainous Afghanistan) compared to lower, slower flying P-3s.
Many P-3 advocates automatically see the P-8's difference as failures, perhaps with much "failure" to be like the P-3.
The P-3 may be suited to low and slow flight with a magnetic anomaly detection (MAD) booms over water. It appears that Indian and UK P-8s are/will be fitted with MAD booms. Australian P-8s might also be so fitted and US P-8s fitted and/or retrofitted with MADs. This is also noting P-8 can fly low when needed.
Low-slow may be useful for Laser or Lidar detection of submarines, but Lidar may be less suited to high-fast P-8s.