Without doing anything to the districts , buffing sea resources would be a great help . Right now they ' re kind of useless , if you basically bring back something like the Lighthouse from V that those tiles are actually useful , it might actually be worth settling on the coast because that means you get more sea resources . Settling on the coast would almost always lead to more sea resources in the city , something that right now isn ' t really an incentive to settle , but I think it should be . You could also give coastal cities 1 amenity by default , similar to how it works with appeal . Wide play is the shit and having 1 amenity in every city basically would be a huge buff , albeit something you ' d notice indirectly . Or maybe coastal cities get a 10 % boost to all trade routes originiating from it . There ' s a lot you can do , aside of all that harbour stuff people are suggesting .