yes, we all know the ai has problems.
and this thread has problems because people are talking about the ai instead of making ships and naval stuffsisies more interesting
As was mentioned above, that was a stupid thing to say. The naval AI is key to improving ships in general.
Anyway, back to the topic. The AI doesn't just attack cities it wants. If it is too far away, as you stated, or indefensible, the AI will still attack it. It solves that problem by razing the city instead of keeping it, which is the correct behaviour.
I know this because I have been actively trying to help out with beta testing. I have removed units from cities that the AI would not be able to hold to make it easy to capture, and they raze it every time. However, these civs were all Evil, so that may explain the razing behaviour. I haven't had good civs declare war on me in 0.20 yet or send out raiding parties (I always choose random civ and have only been good or neutral so far).
On to the naval AI. I am not having the same problems you are. Maybe you are playing on maps with limited oceans, so land based attacks are possible. I think the AI does have an unhealthy preference for land attacks, but it definitely knows how to use a navy when it is the only option.
In my current game, the Calabim see me as their biggest threat (which they should). We are on separate continents, so they have built a huge navy. They have been hesitant to attack me all game and I have not launched a pre-emptive strike either, so we are in a stalemate situation. However, they patrol just beyond my waters with several Frigates (the best war ships they have available), as well as defend their own coast line.
My one problem with their current behaviour is they don't concentrate their forces. Their patrols are all single ships, while they leave whole armadas docked. I understand that they are trying to save on maintenance costs for the ships outside their borders, but their coast guard also exhibits this behaviour. Unless they are planning to launch an invasion fleet, I don't see why more ships aren't patrolling their waters.
However, while they don't stack ships at sea unless transporting units, their coast guard ships sail fairly close together where two of them could attack the same point on the same turn. I have noticed that they will shadow my ships, but they could still have more density though.
One of the biggest problems I see is that the AI is unwilling to launch suicide attempts. I can sail one Man O' War past several Frigates with relative impunity. The AI simply will not attack. Therefore, I can have unrealistically small escorts for my transport fleets, as my opponent's scatter before me instead of sacrificing a couple ships to weaken my Man O' War and get to my Galleon.
On a related note, the AI transport ships flee when they lose their escort, even when they can complete their "mission," so to speak. I had a situation where an enemy approached my territory using Stygian Guard as the escort unit. In the spirit of beta testing, I didn't attack to see where it landed. Then I reloaded and took out the Stygian Guard where the transport fleet could have made it to it's desired landing spot the next turn. Instead of making a run for my shores and dropping off the army, they all turned tail and ran.
Now, maybe the AI valued its fleet more than a punitive attack on me, which makes sense. Also, the Stygian Guard were also obviously a large part of the land force as well, so maybe they decided the army was too weak and it was best to call of the attack. However, I would still look into the code and see if the AI is capable of making a suicide run to drop off an army.
I know this is a long post, so I will summarize here:
The AI should be willing to launch a naval attack when a land attack is possible. This should obviously take into account the unique rewards and risks of a naval attack, including the increased movement speed and the relative strength of the opposing navy for instance.
The AI should not keep so many ships docked. If they have extra ships, they need to camp their fishing boats and patrol their waters in greater numbers. The AI should only gather a large fleet at dock or in the waters around the departure city when preparing an invasion fleet or hiding from superior forces.
When the AI has superior numbers, they should be willing to lose some of their ships to soften yours up and take them out.
When the AI loses its escorts, it transports should be willing to complete their mission.
On another note, the AI should not be able to judge your strength unless it scouts you properly. Whether it is spreading their religion, sending in caravels or whatever, I don't like how the AI currently senses how powerful you are. If I have to send out recon, so should they. ...and no, the power graph does not count as recon.
