Captain Harlock (1978) 1.13

The Castle of Evil in the Sea of Death

The Arcadia returns to Earth and heads to the Sargasso Sea, off the eastern coast of South America. Captain Harlock makes a visit to a military base in South America on the way to their destination. The Arcadia is attacked by a submarine which looks like I-168, a Japanese submarine that disappeared during World War II more than 1000 years before.

The submarine fires a single torpedo, which doesn't do any damage to the Arcadia, and then takes off. The Arcadia follows it. 

Commander Kiruta gets word of Captain Harlock's return after Harlock calls Mayu. Harlock wanted to make sure she was okay. Kiruta leads a squadron of fighter planes against the Arcadia but their weapons aren't powerful enough to damage the Arcadia.

A ghostly battleship rises from the sea and attacks Commander Kiruta and his squadron. Kiruta and his men retreat. The battleship turns and attacks the Arcadia. The older battleship is no match for the Arcadia and is cut to pieces. The Arcadia dives beneath the waves. It finds a dome on the ocean floor. 

There is a graveyard of ships in the dome. The crew descends from the ship to have a look around. They quickly encounter the Witch Aman. She casts a spell on them. They get very drowsy. She is ready to kill Captain Harlock and his crew when the Arcadia comes to life on its own. It picks up the crew and then attacks the Witch Aman who serves the cause of the Mazone.

The Arcadia leaves the Sargasso Sea. Harlock goes to visit Mayu. She tells him about a story she learned, the Tale of Urashima Taro.

Thoughts

The battleship that emerged from the Sargasso Sea looked like the Battleship Yamato to my eyes. The first season of Space Battleship Yamato (aka Starblazers) first aired in Japan in 1974. The sequel series was airing about the same time as this series.

The Sargasso Sea is a region of the Atlantic Ocean. It is north of the Equator. This episode makes is seems as if it is to the east of South America but it is in reality north of South America. 

It is unclear if Aman is a Mazone or not. She is at the very least an ally of the Mazone.