I am liking the blueish one!
However I see now what my problem with the sprites is, the blurriness. I assume that is due
to the Battleship Forever Editor? Or did you change the size afterwards?
Because if thats the case, you might want to consider "cleaning" them up, since they look kinda muddy the way they are.
Won't lie to you, thats a lot more work than creating them from scratch.
So here is my proposition:
Place any of those ships as the bottom layer in GIMP and then draw on a seperate layer, outline and everything.
That way you will learn a lot about how these sprites work and will not only receive a cleaner, better looking version of these ships, but you will also learn a lot.
Which will propably improve your future creations.
However, do what you see fit, I honestly don't know what you could change, besides the things I already mentioned.
If they fit your theme, thats good, if you don't like it, well just do a new one, maybe you will like that one more.