One thing that could make them somewhat easier are harbours being districts now. Since you can build a harbour without your city being directly on the coast it opens up the sea to your one city without wasting precious land tiles. Since land military units spawn from encampment districts I think it's fair to assume that naval units will spawn from your harbour, allowing you to build a navy, trade fleet, and work boats all without even having your city directly on the coast.
Of course, that's just speculation for now, but it'll be interesting to see how it works out.