Question: What part did Rolls-Royce Holdings make for Sea Jet?
Related documents: [0]  [DOC] Rolls-Royce Holdings plc is a British multinational public limited company incorporated in February 2011 that owns Rolls-Royce, a business established in 1904 and today designs, manufactures and distributes power systems for aviation and other industries. Rolls-Royce is the world’s second-largest maker of aircraft engines and has major businesses in the marine propulsion and energy sectors. All of its shares are tradeable on the London Stock Exchange and other markets. [END] 
[1]  [DOC] Sea Jet, or Advanced Electric Ship Demonstrator (AESD), is a naval testbed funded by the U.S. Navy's Office of Naval Research. The 133 ft vessel is operated out of the Carderock Division's Acoustic Research Detachment in Bayview, Idaho. "Sea Jet" was operated on Lake Pend Oreille, where she was used for test and demonstration of various technologies. Among the first technologies tested was an underwater discharge water jet from Rolls-Royce Naval Marine, Inc., called AWJ-21, a propulsion concept with the goals of providing increased propulsive efficiency, reduced acoustic signature, and improved maneuverability over previous Destroyer Class combatants. [END] 
Answer: 
an underwater discharge water jet
an underwater discharge water jet