American maritime patrol aircraft currently carry torpedoes as part of their armament, which serve as key weapons against enemy submarines. As any high-diver of cliff-jumper knows first hand, however, water can feel surprisingly solid after a long fall. Torpedoes still have to be released from low altitude, typically 100 feet or less above the waves. Two recent developments, however, are making this approach less practical for the US military. One is tests of sub-launched anti-air missile systems, using modified short-range air-air missiles that do not require radar guidance. The other is its selection of the 737-based P-8A Poseidon as its next maritime patrol and surface surveillance aircraft. The P-8A can perform low swoops if necessary, but its airframe is really optimized for cruising at altitude.