Imperial Japanese Navy Land Forces of World War II were ground combat units consisting of navy personnel organized for offensive operations and for the defense of Japanese naval facilities both overseas and in the Japanese home islands. It consisted of the following:
The Naval Landing Force or 海軍陸戦隊 Kaigun-rikusen-tai; also referred to as naval shore parties: These were small ad hoc units formed from ship's crews for temporary use ashore.
Japanese Special Naval Landing Forces or 海軍特別陸戦隊 Kaigun-tokubetsu-rikusen-tai: the Japanese Marines. The Japanese formed around thirty-five of these battalion sized units (about 650-1200 men) during the war. Those units which were raised prior to the start of the war had some assault training but as the war progressed the quality of the troops and the training declined and they were used solely for defense and garrison duties. The Rikusentai were not trained to conduct opposed amphibious operations. Though often referred to as "Japanese Marines," they were not a separate military service such as the United States Marine Corps or the United Kingdom's Royal Marines.
The Combined Special Naval Landing Force: combined several Special Naval Landing Force units into a brigade sized unit with greater firepower. There were around five of these when the war ended.
The Base Force or 根拠地隊 Konkyo-chitai and The Special Base Force or 特別根拠地隊 Tokubetsu-konkyo-chitai provided a variety of services both administrative and tactical in areas outside Japan proper, Korea, and Formosa. The Japanese raised around fifty of these units which ranged in size from 250 to 1500 men depending on location and function. The Base Force could also include afloat units.
Defense Units or 防備隊 Bōbi-tai: units of from 250 to 2000 men organized for defense of naval installations and areas of strategic importance within Japan. Some Defense Units included artillery emplacements and some controlled the minefields in Japanese waters.
Guard Units or 警備隊 Keibi-tai: 100 to 1500 men units responsible for ground defense of Imperial Japanese Navy facilities. They were frequently assigned to Base Forces and Special Base Forces. The Japanese raised around one hundred of these units.
Anti-Aircraft Defense Units or 防空隊 Bōkū-tai: Anti-aircraft artillery units of 200-350 men. There were three types which differed based on the number and kind of anti-aircraft weapons assigned. The Japanese formed over two hundred of these units which were primarily located in areas outside Japan, Formosa, and Korea. They were usually assigned to Base Forces, Special Base Forces, Special Naval Landing Forces, and Guard Forces.
Construction Battalions or 設営隊 Setsuei-tai built and repaired naval facilities of all kinds, including airstrips, barracks, ammunition bunkers, and fuel depots on remote islands as well as Japan's major naval bases. Most personnel were civilian employees and unarmed. The Construction Battalions often made use of local labor whose service was compulsory.
The Communications Units or 通信隊 Tsūshin-tai of 100–2,000 men were stationed ashore to provide communications between Japan's widespread naval installations and to and from the fleets and ships at sea.
The Tokkeitai Navy military police units carried out ordinary military police functions in naval installations and occupied territories; they also worked with the Imperial Japanese Army's Kempeitai military police, the Keishi-chō civil police and Tokkō secret units on matters concerning security, intelligence collection, and counter intelligence.
Anti Aircraft Artillery Batteries or 高射砲中隊 Koshaho Chutai were units of forty or fifty men organized for the air defense of important installations and were subordinate to Air Defense Sectors which in turn were subordinate to Defense Units. These batteries were separate from the previously mentioned Bobitai. Several hundred of them were in existence at the end of the war.
