Cap from the Japan Maritime Self-Defense Force (JMSDF), Mine Warfare Force, black with Japan scenes and writing. The JMSDF's main tasks are to maintain control of the nation's sea lanes and to patrol territorial waters. This was presented to Mayor Faulconer by Japan Maritime Self-Defense Force Rear Adm. Hiroshi Oka during a visit to San Diego in August 2015. JMSDF helicopter destroyer JS Hyuga (DDH 181) was in San Diego to participate in multinational, scenario-driven amphibious training exercises.