The Special Naval Landing Forces (SNLF; ) were naval infantry units in the Imperial Japanese Navy (IJN), and were a part of the IJN land forces. They saw extensive service in the Second Sino-Japanese War and in the Pacific theatre of World War II. While not existing as a dedicated naval infantry branch of the IJN, they functioned as the infantry of the Navy, and engaged in many coastal or amphibious operations, leading to them being referred to as "Imperial marines"

or simply "Japanese marines" in the West.

The IJN's marine paratroopers were designated as SNLF units, though they were operationally subordinated to the Imperial Japanese Navy Air Service. IJN armored units were generally subordinated to SNLF units and fielded a variety of light tanks, medium tanks and armored cars.

The SNLF are distinct from the Naval Landing Forces, which were primarily ad-hoc units of naval personnel formed into naval infantry units whom rarely performed proper amphibious operations and were primarily utilized in a defensive role ashore, particularly post-1942, though the SNLF were also employed in increasingly defensive roles as World War II came to a close.

History

Since the late Meiji Era, the IJN had naval landing forces or rikusentai formed from individual ships's crews, who received infantry training as part of their basic training, for special and/or temporary missions. In addition, troops from Naval Bases known as Kaiheidan could form a naval landing force.

thumb|left|IJN Special Naval Landing Forces armed with the [[Type 11 light machine gun|Type 11 during the Battle of Shanghai]]

Starting in the Meiji Era the navy began to raise units unofficially known as Special Naval Landing Forces. These forces were raised from kaiheidan at — and took their names from — the four main naval districts/bases in Japan: Kure, Maizuru (deactivated following the Washington naval treaty, reactivated in 1939), Sasebo, and Yokosuka. In 1927 some of these SNLF units were unified under command of the Shanghai Naval Landing Force and saw action in China from 1932 in the January 28 Incident. Afterwards the Shanghai Special Naval Landing Force was officially formed in October 1932, signifying the first official SNLF unit. Official SNLF units from naval bases were authorized in 1936. SNLF units would once again see action at the Battle of Shanghai and countless other battles and cleanup operations throughout the Second Sino-Japanese War.

thumb|Personnel of the Maizuru 1st SNLF prepare for the [[Hainan Island Operation which included the invasion of Hainan, 1939]]

The strengths of each SNLF ranged from the 200 to over 3000 personnel. Almost all units were a single battalion with a varying number of companies.

In 1941, the 1st and 3rd Yokosuka SNLF were converted to parachute units. The SNLF paratroopers were successfully used during the attack on Celebes and the Battle of Manado. Aside from the paratroopers, there were also planned elite units to conduct reconnaissance and raid operations.

Like all landing forces they often experienced heavy casualties when faced with determined resistance, such as at the Battle of Milne Bay. This was due to their offensive spirit and unwillingness to surrender, and when completely out of ammunition, they sometimes resorted to hand-to-hand fighting with their swords and bayonets. After the failure to capture Milne Bay the Special Naval Landing Forces became a defensive force and very few units were raised. Naval Guard Units became much more common IJN infantry units in the Pacific.

The SNLF gained the distinction of being the first foreign forces to establish a foothold on American soil since the War of 1812, when troops of the Maizuru 3rd SNLF landed on Kiska Island, Alaska without opposition on June 6, 1942 and occupied the island as part of the Aleutian Islands Campaign during World War II. After a year of occupation, with reinforcements from thousands of Imperial Japanese Army (IJA) soldiers, they completely evacuated on July 28, 1943 two weeks before Allied forces landed.

In 1943, a contingent of approximately 1,700 men of the 7th Sasebo SNLF and 2,000 base personnel (mostly the 3rd Special Base Force) at the Battle of Tarawa accounted for over 3,000 U.S. Marine Corps casualties.

SNLF units

thumb|right|6th Kure SNLF in formation at their home barracks in Japan before deploying for the [[Battle of Midway|Midway operation, June 1942.]]

thumb|Japanese Special Naval Landing Forces, members of a , await orders on the deck board of an unidentified IJN vessel in the city of Anqing, China, June 11th, 1938.

Infantry units

  • Kure Naval Base
  • 1st Kure SNLF-At Hainan Naval District, 3rd China Fleet
  • 2nd Kure SNLF
  • 3rd Kure SNLF
  • 5th Kure SNLF
  • 6th Kure SNLF
  • 7th Kure SNLF
  • Maizuru Naval Base
  • 1st Maizuru SNLF
  • 2nd Maizuru SNLF
  • 3rd Maizuru SNLF (Inactivated)
  • 4th Maizuru SNLF
  • 5th Maizuru SNLF
  • Sasebo Naval Base
  • 1st Sasebo SNLF
  • 2nd Sasebo SNLF-Under 32nd Special Base Force, 3rd Fleet
  • 5th Sasebo SNLF
  • 6th Sasebo SNLF
  • 7th Sasebo SNLF
  • 8th Sasebo SNLF
  • Sasebo Combined SNLF (Combined 1st and 2nd Sasebo SNLF)
  • Yokosuka Naval Base
  • 1st Yokosuka SNLF (Originally an SNLF Para formation)
  • 2nd Yokosuka SNLF (Originally an SNLF Para formation)
  • 3rd Yokosuka SNLF (Originally an SNLF Para formation)
  • 4th Yokosuka SNLF
  • 5th Yokosuka SNLF
  • 6th Yokosuka SNLF
  • 7th Yokosuka SNLF

Non-naval base SNLFs

  • Shanghai SNLF (~2000 men): special naval guard based in Shanghai port, China belonged in China Theater Fleet.
  • Hankou SNLF: detachment of the Shanghai SNLF. (Unofficially known as SNLF).

Paratroopers of the SNLF

thumb|right|300px|Organization of the 1st and 3rd Yokosuka SNLFs from 1941 to 1943.

  • Yokosuka Naval Base
  • 1st Yokosuka SNLF (Parachute trained) the 1st was disbanded after its operations in Celebes were completed.
  • 3rd Yokosuka SNLF (Parachute trained) Made a drop on Timor. Later taken into the 1st Yokosuka SNLF.