Blue Submarine No. 6: Saigetsu Fumahito: Time and Tide

Blue Submarine No. 6: Saigetsu Fumahito- Time and Tide is an Adventure game, developed and published by Sega, which was released in Japan in 2000.
Based on the classic manga Blue Submarine No. 6 and its anime adaptations, this post-apocalyptic naval adventure game has players heading up an undersea salvage crew. In its adventure mode, players interact with other players using menu-driven exploration and dialogue. When they step into the sub, players take to the ocean floor in a first-person 3D simulation where they must salvage parts from crashed ships and other things they can find undersea.

The adventure mode features a mix of 2D backgrounds with highly detailed polygonal characters, while key story scenes are told in animated cut-scenes provided by Gonzo, the same studio that animated the 1998-2000 OVA series.