Tide-Line Blue (タイドライン·ブルー, Taidorain Burū) is a Japanese anime series created by Satoru Ozawa and Umanosuke Iida.

Tide-Line Blue is set after an environmental disaster later called the "Hammer of Eden" has submerged 90% of the Earth under water and taken six billion lives.

The series begins fourteen years after that event with the new and remaining countries being brought together under the New United Nations.

However, Gould, a renegade submarine captain wishes to use military force to create peace in the new world order, while Aoi, the secretary-general of the New UN, wishes to use diplomacy, and a boy named Keel finds himself caught up in the middle of it all.

Opening Theme: Ending Theme: Tide-Line Blue was published on DVD in North America by Bandai Entertainment and dubbed into English by Blue Water Studios.