Fushigi no Umi no Nadia: Nautilus Story is a oVA anime.

About the production: the story comes from an original script, there are 3 episodes of about 100 minutes and its current status is "finished".

Its main genres are action and adventure.

On AniList, Fushigi no Umi no Nadia: Nautilus Story has an average score of 63%, an average score, and appears on 542 users' lists.

A shorter, more streamlined version of Nadia called "The Nautilus Story", which all but eliminates the filler arc and concentrates on the struggle between Nemo and Gargoyle. Some scenes in the more pivotal episodes are cut as well. The compilation series was made by Hideaki Anno, who was said to have been dissatisfied with the final result of the TV show. The Nautilus Story was only released in Japan on VHS and laserdisc. (Source: TV Tropes, edited)

Official synopsis from AniList.