Talk:List of submarines by upgraded maximum stats/@comment-1838919-20140202234530/@comment-24155103-20140202235151

They're terrible at <20, acceptable at ~30 and really start to be good around 50. You'll need to work on leveling it up, in the meantime, it's mostly a way to divert damage from your other ships.

You'll want a Hyoteki on it at <10 so it can shoot pre-emptive torpedoes, still a good choice all the way till you can remodel it due to the +12 to Torpedo stat. Post-remodel you'll want standard torpedoes to enable cut-in attacks, much more valuable than a few points.