This paper presents an overview of the development and present state of the art of hybrid propulsion drive systems as applied to high-performance naval combatants. Motivations for implementing hybrid electric drive architectures are reviewed including potential benefits in term of fuel savings/reduced emissions and additional power generation capacity. Both back-fit into existing propulsion and power generation architectures as well as forward-fit are discussed. Issues associated with coupling the mechanical drive train and electric power generation system together are reviewed.