That Time I Reincarnated as a Shipgirl

Imagine, waking up in your own life. Accept, it's not. Instead, you've de-aged and swapped genders. Meaning you have to rebuild your life from scratch. And now there are murderous monsters prowling the seas, intent on exterminating humanity from the Earth. At least I have to perk of being completely landlocked. Wait? I'm a shipgirl? Well, there goes that idea.