A large force consisting of two heavy aircraft carriers, one light aircraft carrier, a seaplane carrier, nine cruisers, and 13 destroyers—split into several elements—was to guard the Japanese Port Moresby invasion convoy as well as to engage any Allied naval warships that approached to contest the invasion. The Tulagi invasion force, consisting of the destroyers and ; minelayer/transports , and ; auxiliary minesweepers "Wa-1", "Wa-2", "Hagoromo Maru", "Noshiro Maru #2", and "Tama Maru"; transport, "Azumasan Maru"; subchasers "Toshi Maru #3" and "Tama Maru #8"; and commanded by Rear Admiral Kiyohide Shima (flag on "Okinoshima"), departed from Rabaul on 30 April and headed towards the Solomon Islands. Rear Admiral Aritomo Gotō provided air cover for the Tulagi invasion with his Covering Group of one light carrier (), four cruisers, and one destroyer located just west of the central Solomons. A separate Cover Force (sometimes referred to as the Tulagi Support Group)—commanded by Rear Admiral Kuninori Marumo and consisting of two light cruisers, the seaplane tender , and three gunboats—joined the Covering Group in supporting the Tulagi invasion. Once Tulagi was secured on 3 or 4 May, the Covering Group and Cover Force were to reposition to help cover the Port Moresby invasion.