This is what I found

In port Mirren there use to be a island keep , so I thought I just have a look if anything has changed. Well this is what I found. First as the pictures show there is a boat to take you to keep island, but once you get there the lot icon says water city. I wonder what happen if you claim it will it be just another water city or will it turn into a keep island

 

It is just a water city lot when you place a house there, but I think it was a test ground for what could become the island keep. I think it's cool you get your own little boat and private spot though.

 

if you have a keep deed it used to turn into that elusive island keep everyone is complaining about, if you place a boat there it become a boat.

It is just a City Water Lot, houses make it what it is.

 

I would loved it but I have already place mine. However if I fail to place in a good spot in july I may try here