Blue Submarine 6

In the near future, the oceans have risen, flooding all land at sea level and threatening to submerge remaining land masses in short order. As if that weren't trouble enough, humanity has found a new enemy in Zorndyke, a mad scientist. He's gathered an army of ocean-dwelling creatures and declared war on mankind. It's up to the state-of-the-art Blue Submarine No. 6 and its intrepid crew -- including Tetsu and Mayumi -- to ensure humanity's survival.