That sounds amazing! There are a bunch of animes that are unwatchable if you don't remove all the fillers. Or in case of naruto, all fillers and flashbacks, lol
Nadia: The Secret of Blue Water is one of my all time favorite anime. While I think that many criticisms of the island arc are valid, I don't think it should detract anyone from watching it from start to finish and I wouldn't recommend skipping it, either.
While I'm happy that someone went to the trouble of recreating a different cut of the show based on official work, I don't know that it's really even necessary, just as I rarely find those sorts of efforts (which happen somewhat frequently in anime, where they condense tv shows into movies) to be very good.
Yeah, I'm not sure I would recommend somebody watch The Nautilus Story first, unless maybe they couldn't find the time or motivation to watch the full thing. Nonetheless I think The Nautilus Story is pretty cool for what it is, and perhaps even ideal for somebody who wants to rewatch Nadia but doesn't want to rewatch all of it.
For reference, The Nautilus Story clocks in at 5h30m, while the full show is something like 20 hours. So TNS is a substantial streamlining, removing a lot more than just the island episodes. But this might be what some people want.
While I'm happy that someone went to the trouble of recreating a different cut of the show based on official work, I don't know that it's really even necessary, just as I rarely find those sorts of efforts (which happen somewhat frequently in anime, where they condense tv shows into movies) to be very good.