Slitherine

Playing around with the editor and looking at the unit files and I was wondering if I added an Aichi13A JAKE floatplane file and modified everything to it to mimic a The Yokosuka E14Y GLEN submarine floatplane and added a stock submarine and made it able to launch when surfaced would that even be possible. I know how to add a plane into a hanger from reading the forum and have the mission editor handbook.

Or is adding any unit and using an existing unit as an aliases even possible.

Love the game.

Hope the developer add a Spritepack like HOI3

Not through the editor.

Perhaps it can work as a mod if you edit the units.csv file add a submarine as valid "carrier type" and make sure that submarine unit type has 1 cargo slot.

I've not tested this myself though, so no guarantee it works. Having an I-400-class submarine would be cool - although probably not super useful in the game

Thanks for getting back and ideas how it may happen. I now know was a bit to ambitious in my question.
Currently I'm learning/stuck in just aliasing an H6K MAVIS in the game from the in game H8K EMILY.
Once I get the basics down with that I will attempt a submarine with seaplane launch capability.

Baby steps first.

Well I answered. It IS POSSIBLE to base a floatplane on an IJN submarine.
The submarine will dive, surface, cruise and retrieve the plane and launch the plane just like any surface ship.
Good News

But the Bad News is it can do this both surfaced AND SUBMERGED
But If I was SBS or some commando that would be a cool feature to have being based on a sub. I know the Australians Commandos were on American subs during WWII.
Just bashed together some data, threw an icon picture that doesn't match sub and other issues... but no crashes. I'm sure it will work for a Makin Island Raid using Marines.
Or those pesky iBoat supply runs to New Guinea.
I just aliased a Japanese sub and a small added edit to the Aichi floatplane in the unit so it can be handled by a submarine besides battleship, cruiser et al...
After that- everything was JAKE

One more screenshot showing the sub has compartment added to carry and retrieve a/c