Cargo ships to transfer 1000 artillery shells are not that bad, since that's equivalent to 10 artillery wagons, but an artillery ship would be nice. Artillery ships with multiple turrets and different range dynamic would be interesting as well

Whenever I get around to the code for adding new ships XD. My dream is for someone like KingJo to make models for a battleship, patrol boat, and a landing craft.

I figured art/models are the major hindrances. As an indie dev, I feel ya.

Whenever I get around to the code for adding new ships XD. My dream is for someone like KingJo to make models for a battleship, patrol boat, and a landing craft.

I mean
I've never made the models for my mods myself anyway. I just took what was free on the market. So if it's just you needing the models and sprites, that can be arranged. That's not hard.

I have basically gotten the "add new ships" interface to work in my testing branch. I made a vanilla artillery wagon drive on the water! Where can one get a decent battleship sprite? The really hard part will be animating the turret correctly.

I nearly always got my models from Sketchfab. I would start there. https://sketchfab.com/search?features=downloadable&q=battleship&type=models

And animations arent that hard. I see bigger problems in making the different sheets for the artillery XD

I feel like if combat ships were put in, then the biters need a way of retaliating….

I am beta testing a version of Cargo Ships that allows other mods to add new ships. It is possible to make an artillery wagon-type ship that rides on waterways.

See https://mods.factorio.com/mod/cargo-ships/discussion/6289c16d1c6416b4cd7e0a53