The sorties of free souls

This story is based off the Japanese browser game, "Kantai Collection," otherwise known as "Kancolle." In this game, there is no story, but there are many ship girls, who have their own characterization. There are many theories within the fandom, and a fan theory that I've created is that the ship girls are probably just girls who end up taking the souls of ship girls, and fight against these things called "abyssals." What I believe these abyssal are, are the souls of sunken ship girls. There are plenty similarities between some ships and abyssal, so you should look into it yourself. There isn't much more to that, but that is the premise I will put on for this story. I will try to follow these off, with real life historical events, please tell me if I get something wrong. Of course, everything won't be 100% canon, but I'll see what I can do for this story.