Suddenly, a fleet of ships with mysterious superweapons called the “Fleet of Fog” appeared all around the world. Humanity didn’t have the technology to fight such a fleet, so they were driven out of the sea...

Seventeen years after the battle, for some reason, Gunzou Chihaya and his crewmates aboard the I-401 and the personification (Mental Model) of the I-401, Iona, started fighting the Fleet of Fog...  

Kenn's Comment: Great read. Action is well paced, and the story isn't bogged down by constant technical explanations. The art is great, and there are small bits of comedy every now and then. The protagonist has a good head on his shoulders too, which really helps. Better than having a Naruto or Bleach with battle-ships. Good grief, I think I'd burn anything like that instantly. After all, losing a battle with a ship usually results in it either sinking or exploding. Both ways, you're more or less done for. Technical details are usually at the end of the volume, often explained by two characters (can't remember if they ever show up in the manga or not).

Looking at past works of Ark Perf., they're no strangers to the field of mechanized warfare, with several Gundam manga adaptations under their belts.A rather...straight-laced no-nonsense friend of mine recommends this one too, so you can rest assured that it's good.