Securing Energy for our Armed Forces Using Engineering Leadership Act of 2019 or the SEA FUEL Act of 2019 This bill directs the Department of Defense to carry out a program of research, development, testing, evaluation, study, and demonstration of technologies related to blue carbon capture and direct air capture, with the goals of developing technologies to turn carbon dioxide into clean fuels, creating products for military uses, and using the technologies at military facilities and in military transportation. The bill defines "blue carbon capture" as the removal of dissolved carbon dioxide from seawater through engineered or inorganic processes and "direct air capture" as the use of equipment to capture carbon dioxide directly from the air.