I created this because I thought the lack of fishing was sort of silly since fishing has been an important food source since the dawn of man. This adds a fishery to kingdom players that will be available to any coastal town level 2 or above once the kingdom has researched Seafaring. It adds 8 food (as fishing is a year round source of food, unlike farming...this is the logic for double the food points. If this is found to be too high, I'd be happy to lower it.) I'm still having a little bit of trouble getting the tile placement to behave, but it's not due to anything on my end...I have the same problems with the standard 'harbor' improvement.
Here's the download link, installation instructions are in the rar file, please read them, as the two folders need to be extracted to different places in order to make this work correctly.
UPDATED to 1.1
Added an Empire version...
UPDATED to 1.2
Fixed an XML error.