List of submarines by upgraded maximum stats

Ripped from an answer to a comment question:

Chill man, you've got a rare shipdaughter, you ought to be relaxing a little.

Submarines can only be shot at by light cruisers, torpedo cruisers, and destroyers.  In addition, any of those enemy ships are forced to attack them -first-, meaning your other ships get away with no damage for free.

Submarines are also the most resource-efficient class in the game, they cost almost nothing to deploy, and in addition the two or three expeditions you can send them on are very very cheap because of this.

If you have midget subs off of Chitose or Chiyoda's 2nd upgrade, you can put them on a submarine for that extra attack before gunfire phase.  After you get a submarine to level 10, you can actually take the midget subs off because they'll have that initial attack without any equipment at all (put regular torpedoes on to boost their stat, or a turbine to help with their low evasion).

Once you level them up a bit you can take them to 2-3 and leave the stage as soon as you hit a fuel node.  Easy fuel.

Good luck.  Run silent.  Run deep.  Run subdaughters.

• Green : Outstanding

• Yellow : Above average

No.	Name	Class	Mod Lv														Notes
126	I-168 伊168改	Kaidai VIa	50	11	69	0	0	29	10	15	18	49	Slow	0	10	20
127	I-58 伊58改	Type-B Mod.2	50	12	84	0	0	39	50	18	19	49	Slow	2(1,1)	10	25	Doubled repair time after remodel, can launch seaplanes