Lord Azazel, thanks for confirming. I do have coastal cities with harbors in the game and the city transfer button is greyed out.
browd, thanks for moving the thread to the appropriate forum. it's where i was going to start this thread but wasn't certain it belonged there.
I suppose I'll always the memory of my first great admiral relegated to presiding over a mighty four tiles. Perhaps i should retire him and turn him into an ironclad with one promotion...and then put the unit to sleep. despite maintenance costs, i'm not certain i have the heart to delete the unit.