That sounds very VERY stupid. I can see why its so popular.

I have a policy to take a poke at whatever's trending, so a while back I had a stab at it and found out this girl IS a ship, well, sort of… basically it's like magical girls because certain conditions:
1) Female
2) Obscure power that's not explained properly (in this case they have the souls of once existing battleships, hence named after them [angry logic noises echo in the room])
3) Some sort of attachments/decorations to say "hey look, it's a ship for real" hence the head ornament.

Stuff happens, but in such an overly-moe fashion that I had to stop before investing more than one hour of my attention, otherwise it would legally form a commitment to watch the season through to the end.