Seaport's nickname "Wanko" is because of the first part of her name "港湾", or "Kouwan". Specifically to this comic, her twintail hairstyle earlier and Airfield-chan's pun probably had something to do with it too.

Heart-breaking, in a way. There just isn't enough Wanko to go around.

So the I-class destroyers are stray cats then? kinda cute way to think about it.