possible to change "max number of ships" after gamestart?

[Alneyan]

It is indeed in the settings file, and these two lines govern the default value:

Default Number Of Units Per Player := 1000
Default Number Of Ships Per Player := 200

As it is a default number, I am afraid they won't help a game which has already been started. If you have too much free time on your hands, you might try to edit the game file itself and look for the hexadecimal value of the maximum ships, but I am not sure if it would be fine with SE4.

[Kamog]

I don't think you can edit the save game by looking for hexadecimal numbers. The data appears to be encrypted.