Acording to many problems with too much port for one nation... i think everybody know it
why do let it be like this with 3 changes:
1. wipe all ports
2. set new price for flags... (nation with 3 towns pay 100k for flag, with 4 towns 150k, 5 towns 200k etc +1 town = +50 k gold)
3. new stronger towers or one big very strong port (acording to it purpose... capital biger, deep port medium, shallow small etc)