1954 my friend!
I saw it when it was new, and I remain impressed by the effort. James Mason as Nemo! How could you go wrong.
One thing though, on seeing it in recent times: the scene where the natives get a dose of the electrified deck is actually "racist" in the sense of the accusation that is so often made. Aside from their reaction to electric shock, which might be excused as natural, there is the depiction of their language, which consists of simple gibberish, such as "Uga bugga bugga" in repetition. I'm sure they were just following direction!
Wow, I did not know it was that old. I was 7 in 1954 so probably saw it when it first came out.
I dunno, could be considered the forerunner of modern Chicago Ebonics and rap.