During an age transition to the modern age a naval commander and 4 of my ships got placed in an inland lake. I am unable to get them out of the lake. I tried to transfer the ships to a different commander, but that did not work. I am going to have to disband them as they are useless now.
But in general I really don’t like how my army and navy get scrambled during age transition. It seems random and I have to spend several turns sorting it out.