Hi, from what I've seen the water tiles yields are 1 food and 1 gold even for lakes which is not very good. The harbour district has a 1 gold adjacency bonus per coastal ressource and the lighthouse doesn't improve water tiles yields. I'm not sure but I don't think that the shipyard improves water tiles yields but tell me if I'm wrong. Is there another building in the harbour ? I saw somewhere that there is a hotel resort improvement for coastal tiles or tiles next to water but I'm not sure. Anyway this improvement will come lately and before that I have the feeling that coastal tiles will be considerably worse than land tiles since there are only two luxuries available, a weak base yield, no improvements on tiles without ressources (unless you can build fishing boats in every coastal tile) and no districts except the harbour. What do you think ?