The 1st Yokosuka SNLF (Special Naval Landing Force) was formed 20 September 1941, at Yokosuka Naval District, round a battalion of 520 paratroopers. The 2nd Yokosuka also formed at the Yokosuka port area, 15 October 1941, with 746 men and trained as such, took no part in any airborne operations and became an island defensive base unit. The 3rd Yokosuka was formed on 20 November 1941, again at the Naval facility and consisted of 850 men. This unit was involved in the invasion of Dutch West Timor as airborne inserted infantry, setting off from the captured air base at Kendari.