Doraemon Movie 04: Nobita no Kaitei Kiganjou

Nobita, Doraemon, Shizuka, Gian, and Suneo choose the ocean for their summer adventure, using futuristic equipment to travel and camp beneath the Pacific. Their search for excitement leads Gian and Suneo toward a legendary sunken treasure, but the deep sea hides far more than an old ship.

The friends are taken to the underwater kingdom of Mu and learn that its ancient rival Atlantis is now controlled by machines. A dormant defense system has mistaken natural activity for an enemy attack and is preparing nuclear weapons that could devastate Earth. With the surface world unaware of the danger, Doraemon and his friends must cross into Atlantis and stop a war no human knows is about to begin.