'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 11^th Construction Unit and 13^th 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 8^th Fleet, was assigned to transport the 5^th Sasebo Special Naval Landing Force to Guadalcanal.