Sand cargo ships have been active in the Ieshima region since the days of the motorized sailboats and they used to transport river sand mined in Okayama, Tokushima and Wakayama Prefectures.
With the advancement of steel ships, Gatt ships equipped with mining equipment on-board were used to mine sea sand in the Seto Inland Sea area.
Due to a prohibition on the mining of sea sand now, the ships provide transport services for sand shipped from Kyushu and Shikoku instead.