在这部高校舰队动画片中,故事发生在遥远的未来，彼时，大陆板块的活动令海水渐渐淹没了日本的大部分国土，人们不得不在海上建造起新的都市。随着时间的推移，海上都市的规模越来越大，航路越来越复杂，为了维持秩序，一种人们称之为“蓝色人鱼”的新型职业渐渐被大众所接收和憧憬，这份光荣的职业亦成为了很多女子高中生们未来奋斗的目标。
活泼开朗乐观向上的岬明乃（夏川椎菜 配音）、沉默寡言外冷内热的宗谷真白（Lynn 配音）、害羞内向但在熟人面前有着十分可爱的一面的立石志摩（古木望 配音）、傲娇毒舌非常在意自己身高的西崎芽依（种崎敦美 配音），这些个性迥异的女孩子们，是否能够实现她们心中的理想呢？
15 year old girl Misaki Akeno aspire to become a Blue Mermaid, a group of women trained to operate navy warships for the purpose of international peace and handling maritime disaster. She attended Yokosuka girls High school where she became the captain of the Harekaze with her classmates as her crew. Unfortunately, their instructor attacked them in their first day for no reason and they defended themselves against the attack which makes them to be hunted by the authorities as fugitives although this weird incident are more than meets the eye.
没有把握好世界观与剧情之间的平衡。相知相拥。不知道制作组到底想干嘛。这或许是实验动画——《青春波纹》观后感。高校舰队。迷之海上安全整备局。艦長啊就不知道，一個提督的命運自己不可以預料。
