Arr pirates!! I be sharing with ye a trick that allows ye to have more resources than your capacity allows. Normally if your capacity is reached yer Haven will not produce any more of gold or lumber or rum depending which one is full, so it is not a good idea to be there, but there can be many reasons ye keeping high level of resources - maybe adding up to make a big building upgrade.
So if ye reach yer capacity, most often this happens with Rum, then one simple trick ye can use is to put yer Rum for sale either at a 1:2 ratio if ye actually wanna maybe sell it or at any other ratio which means most likely ye will never sell it and then this Rum gets taken out of yer Haven and yer capacity drops. Any time ye need that Rum ye just go and cancel yer offer and all the Rum comes right back to yer Haven and ye don't even have to wait for it.
Here the example how at this time I was keeping more than 10,000 Rum extra using this trick: