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.
A stern drive engine is mounted directly to the transom of the boat (unlike an outboard that is more easily 'removable'). A Jet engine is an engine that cycles water through jets and pushes the water at a rate fast enough to push the boat - most PWCs and small speed boats use this water 'jet' power. Sailing is the use of wind as propulsion. And finally, human power is normally considered for paddle boats, canoes, kayaks, and such.