model doesn't generate specific characters, it copies the basic concept
it took a lot of continuous training 659 images are divided into three categories "ship girls" "submarine" "aircraft carrier" the last two work not to say that well. there are much fewer images in them.

I recommend using ultra-high final resolution, I personally generated at 1696\2264
you can try add more strength to trigger tags, or rearrange the tag hierarchy and maybe you will do even better results than presented here

tag 1 - ship girl, ship canon

tag 2 - ship girl, aircraft carrier

tag 3 - ship girl, submarine or just submarine (may wont work at all)

additional tags may help - torpedo launchers, torpedo

work strength - 0.8