This story, in the universe of Suisei no Gargantia, follows Bellows, a
side character in the original series, where the planet is covered with
water and humanity lives in various large fleets of ships. The story
begins three years before Ledo (from a spacefaring civilization)
arrives. When Bellow's fleet is destroyed, she is rescued by a fleet of
salvage ships, which send teams of yumboros (human operated excavation
robots) under the water to recover goods. Her skill with yumboros is
valued by her new fleet, and she soon joins the salvaging team.