1 Clinical Psychologist: Doctorate Degree in Psychology (4 to 7 years of graduate school) 2  Industrial-Organizational Psychologist: Master's Degree (2 to 3 years of graduate school)  Forensic Psychologist: Master's Degree (2 to 3 years of graduate school); a doctoral degree is recommended.
Submarine Propulsion Systems. During World War II, most American submarines were powered by diesel-electric systems. This was a departure from earlier submarine power systems, which were direct drive types, little changed from the earliest boats. In this direct-drive power system, the diesel engine is directly connected to the propeller shaft.
Attack Submarines - SSN. Attack submarines are designed to seek and destroy enemy submarines and surface ships; project power ashore with Tomahawk cruise missiles and Special Operation Forces (SOF); carry out Intelligence, Surveillance, and Reconnaissance (ISR) missions; support battle group operations; and engage in mine warfare.