#1 It’s a failed experiment
Blue Submarine No. 6 is a late-90s OVA adaptation of a manga from 1967, which dealt with an apocalyptic war between humans and monsters, amidst the ruins of a world ravaged by climate disaster.
Production of the anime was handled by Gonzo and the decision was made to experiment with a relatively new technique, whereby traditional animation is mixed with 3D computer graphics. Quite a daring move in 1998 and one that doesn’t pan out very well at all. Some effects like the water rendering can look nice in isolation, but when mixed with the normal animation style it runs into all kinds of issues. CGI creatures and structures look detached from the rest of the show, characters on water end up looking like 2D sprites, and in general it just prevents the series from ever looking like a consistent, unified whole.
Not content with just experimenting with the visuals alone, the soundtrack was put into the hands of a band called “The Thrill”. As a result, climactic battles with the future of the human race at stake end up being set to cheery jazz music.
#2 Horrendous audio mixing
Speaking of music, the anime has problems with its audio, at least in the English dub. The volume and quality of the voice acting is all over the place, which mean you either need to constantly adjust your speakers or turn on subtitles just to be able to catch everything.
The monster characters have this annoying “evil” filter over their voice, making them exceptionally loud, yet still difficult to understand. The sound is so warped that I couldn’t make sense of half of Verg’s dialogue, and wasn’t even sure if his voice was intended to be male or feminine for the longest time. On the other extreme, you got characters that are so soft-spoken that dialogue almost sounds like a whisper, especially when the camera pans back and their volume is dialed down even further.
Additionally, the performances in both the sub and dub are just plain underwhelming, sometimes to the point of being plain annoying to listen to. For example, Verg doesn’t have the dumb audio filter over his voice in Japanese, but then he just sounds like a generic anime teenager with a separate track of monster grunts being played over his dialogue. It’s painfully bad to listen to.
#3 Barebones plot
Though I have praised post-apocalyptic settings like this before, such as in Arpeggio of Blue Steel and Neon Genesis Evangelion, Blue Submarine No. 6 doesn’t really do anything with the premise.
With only 4 episodes there isn’t much room to expand on the anime’s universe and backstory, so you are just thrust into this doomsday narrative with no context besides a magazine cover alluding to some mad scientist. The plot is rushed and largely driven by battles interspersed with brief moments of downtime for flashbacks and plot developments, which is nowhere near enough to develop a connection with the cast or significantly expand on the storyline.
Blue Submarine No. 6 sometimes has hints of potential, but so little room to develop them that they end up feeling generic or underused. Several supporting characters are present so little that you forget they’re even there, which is most tragic in the case of the African navy captain Gillford N’duhlle, whose character arc is so transparently rushed that it ends up feeling like a joke.
Kino suffers the same fate despite being one of the anime’s main protagonists. The concept of a headstrong, but exceptionally young soldier being put into a position where her actions can decide the fate of the world is interesting and could be used as a catalyst to explore her changing worldview as the story develops. Instead, the focus on male protagonist Tetsu means her role is never developed much beyond her basic “get revenge” motivations, ultimately rendering her shallow.