There was a Japanese cartoon when I was a kid about a battleship in space. Only saw a few of them. Not sure why this tread made me think of that. Don’t know the name of it but would have been early 1970s.
I think you’re referring to Starblazers. In Japan, it’s called something like Space Battleship Yamato. In the show, the UN (or whatever) raises the Yamato from the ocean floor and refits it as a space battleship to meet threats to the Earth. That show was huge in Japan. There have been several additional movies and series of anime that advances the story after the original A few years ago, they did a live-action movie called Space Battleship Yamato.
…But I’m like you. I’ve only seen a handful of episodes and it’s my store of trivial knowledge about cartoons and science-fiction that I’m able to answer at all!
If you’re into history, there’s a movie the Japanese maid about the _real_ Yamato’s final mission against the US Navy you may want to check out.
Another popular anime that came to the US in the early 80’s was called Robotech. It was an amalgamation of three different anime series artificially strung together as one long series. The first third of the series was much like Starblazers with a space battleship (that could transform into a giant space robot!) full of fighters that went out to defeat an alien menace.
Space Battleship Yamato