After the first Antarctic observation, the Soya underwent major modifications for the second and third observations. The front deck was changed to a flat state without any cut-outs on the side of the ship. A deck for launching and landing a large helicopter was added. The bridge was extended to the side. A forward portal mast was added and the rear portal mast was moved. A thin bilge keel with four sections on one side was installed. A large helicopter was installed, etc. Especially in the third renovation, efforts were made to strengthen the air transport capacity by large helicopters, so that even if the Soya cannot approach the base due to worsening weather conditions, it is possible to transport people and supplies sufficiently.