Maybe I’m doing this wrong, but I’ve been starting to come to the conclusion that ocean fish are a bit pants…
By my usual methods (work/chop a forest), a city can have a monument in 4 turns. This means that the fish is improved in turn 15. By this point, the dry rice city has a lead of approx 25 food on the ocean fish city (not to mention 60 hammers saved). So the ocean fish city is catching up earliest after 40 turns? I say earliest, because the dry rice city can put those 60 hammers towards a granary and keep the lead for a while longer?
In a world where snowballs are important, that seems quite a long payback?