Playing against AI, I had a minor faction unit [hurnas] begin to siege my capital during the winter, with the ice shelves activated. I rushed some units to break the siege, but by the time I got there, winter ended and the ice shelves melted away. I assumed this meant that the minor faction would turn into a boat [theyhaveShipyardsresearchedbydefault,sowhynot?] and the siege would end.

So I was right in that the Hurnas DID turn into a boat. However, the siege didnt end, and since they were an aquatic unit, I couldnt engage them to break the siege. Sucked to lose 4000 science output a turn to 4 Hurnas in a boat, but there really was nothing I could do.

Pretty sure naval combat was mentioned to be a thing in an upcoming update, but it shouldnt be working like this!

Upload save game file

First time I see this. ^^