Ah I see. Thanks for the clarification 

What map type were you playing on? It must have been Pangaea! I could see not needing a navy on that map type (which is why I avoid it). Continents and Islands would definitely require a Navy unless you go the isolationist route and send no trade routes over to other continents.
Question on that...does the carrier get any experience besides being in combat itself ( like experience when its planes perform an attack)There is one ship no one has mentioned (if i missed it skimming sorry)the aircraft carrier with 2 bombers on that sucker and you can destroy cites deep inland! naval projected air power is great. I build one for lulz on pangea and it was surprisingly effective.
Trade route range is doubled over water. If you want your coastal city to be a trade hub, you need to put it on the coast otherwise you'll only have access to about half the total area as you normally would otherwise, compared to a city 3 tiles inland with a harbour. You'll have to take my word for it or do the math yourself. I've already posted it in another thread and I'm too lazy to look for it.
The Sailing Eureka is NOT worth settling on the coast right now. Settling on the coast, in the best case scenario, guarantees you at least 3 tiles of water, which is very very bad currently in terms of yields. The only district you can build on it is the harbor, which doesn't help with the general poor yield, and can be done even if you only have 1 tile of water. The other added benefits are the tiles on which to build aquatic wonders, but those are too conditional to be advisable when deciding on the right tile to settle, especially since land tiles are just so much more versatile. Water resources aren't that valuable either.
This is all without mentioning the vulnerability to melee naval attacks.
Return the water tile yield bonus from lighthouses and seaports, and then it will be worthwhile. Also, if crabs become luxuries again, it will help increase the value of coastal settlements in general.
The Sailing Eureka is NOT worth settling on the coast right now.
But getting access to early ships is, without need to build expensive district. Just make sure to minimize number of ocean tiles in the city.
How getting ships early is useful ? No maritime trade routes to protect, no coastal cities no defend except the one you built and unless you play on island map few cities from the ai to conquer. Anyway your arguments are also true for the previous civ games and the coastal tiles weren't as bad as now. Right now water tiles are the worst tiles in the game besides mountains. Their yield is so bad that you will never work it and you can't build districts besides the harbour. At least if you build a city with half grass half desert you can use the desert tiles for placing districts so you don't use good tiles for them. In a coastal city you will have to share your land tiles between mines, farms and districts.But getting access to early ships is, without need to build expensive district. Just make sure to minimize number of ocean tiles in the city.
Question on that...does the carrier get any experience besides being in combat itself ( like experience when its planes perform an attack)
Harbour district from an inland city do not benefit from this doubling of trade route range? only coastal cities do?
I guess the plus side, if you consider it that, is that at least Germany's UU is a naval unit and generally not very useful,