'Sn' (ii) was a Japanese undertaking to establish air bases in the South Pacific area (June/July 1942).
On 29 June the 6,702-ton ammunition supply ship Kotoku Maru departed Truk atoll in the Caroline islands group bound for Guadalcanal via Bougainville in the Solomon islands group carrying airfield construction workers in a convoy with the 6,645-ton naval transport Azuma Maru, 7,613-ton naval refrigerated cargo ship Azumasan Maru, 5,046-ton naval transport Hokuroku Maru, 5,627-ton naval transport Meiyo Maru, 8,606-ton naval aircraft transport Kanto Maru, and 7,025-ton naval auxiliary transport Matsumoto Maru escorted by light cruiser Yubari and the destroyers Akikaze, Oite, Uzuki and Yuzuki.
As well as equipment and supplies, the convoy carried a special naval landing force and the 11th Construction Unit and 13th Construction Unit. These last were landed at Lunga Point on the north coast of Guadalcanal on 6 July and immediately began work on the construction of an airstrip which, once taken by the US in 'Watchtower', became the basis for 'Henderson Field'. On 1 August Meiyo Maru arrived at Rabaul, New Britain, and after being attached to Vice Admiral Gunichi Mikawa’s newly established 8th Fleet, was assigned to transport the 5th Sasebo Special Naval Landing Force to Guadalcanal.