stealth_nsk
Deity
But there's no reason to think that harbors can't be pillaged same as other districts. So if your only access to the sea is through harbors, then your naval power is at a very real risk.
This change actually makes me think Navy's are stronger - as now they can actually blockade your ports of call with little-to-no risk of retaliation from anything other than the navy as harbors can't fire like a city could. So really, all you need to do is defeat an enemy navy, destroy their harbors, and they'd never be able to take the ocean back from you.
If your city and/or encampment are near harbor and you have walls, you surely could retaliate. But surely it's not as strong as city itself.