Comment 1 for bug 1389211

If you want to test it, you might use my branch seafaring-ai, watch the output to console for text ' port without portdock at ...x...', so you can pause and investigate the port.
It starts to appear after couple of hours of gameplay, and then after some time game crashes.
You can use new version of soutfall islands map in map section on the website, because there is not enough good maps for seafaring. One reason is that AI cannot work with maps with multiple waters.