How do I stop a city being Blockaded?

[Xintao]

The AI in my game keeps blocking my trade. I can not figure out how to prevent or stop this.

Thanks, Xin/Jeff

 

[elmurcis]

Need to sink ship that do that (if at war or if that is Privateer that AI/you can use at peace) or make peace.

 

[Emperor Ukunaka Kukvlkana]

you're gonna need a bigger boat

 

[TheNoseKnows]

I wouldn't feel too bad about not understanding the blockade mechanics. They're actually pretty broken:
http://www.sullla.com/Civ4/RBPB2-11.html

Why is Vicksburg starving?!? Oh wait, it's "coastal blockade", the single worst feature added in the last expansion. Kathlete's dinky little galley is able to deny us from working TWENTY-FIVE coastal tiles, and cut off all of our resources from this island. Vicksburg has basically been crippled completely, due to the presence of two little galleys. It's even more absurd up at Big Bethel: despite the fact that we have a trireme parked on top of a crab resource (1 NE of the city), the Ottoman ships can prevent us from working that tile by instituting a coastal blockade. They don't even have to attack our own defending ship! Coastal blockade overrides everything in this game. It's literally impossible to defend your own sea resources, since the blockading ship doesn't even need to control the tiles to deny access to resources.

I'll just stop here by pointing out that Alex Mantzaris (alexman) put this into the game over vehement protests by Speaker, and that he's a farking idiot who had no business directing Beyond the Sword. Good thing he no longer works for Firaxis....

Speaker, it's not quite as bad as it looks here. I roaded our rice and wheat which added +4 health and helped mitigate the starvation a lot. We also get +3 happy back next turn as a draft penalty wears off, and that along with a whip on the caravel to bleed off some unhappy pop should get us into a safe zone at Vicksburg. Doesn't change the fact that this game mechanic is stupidly broken though.

athlete made use of his naval advantage to "coastal blockade" our cities on the island to the northwest. While I think the idea is sound in theory, it's completely flawed in practice, as demonstrated by the dinky little Ottoman galley being able to blockade tiles that it can't even move to! (How can a two-move galley stop you from working the sea coast four tiles away?!) Even more absurd was the Ottoman caravel denying us a clams tile that another ship was defending, without even having to attack or gain control of that tile. Yep, this is pretty laughable.