Dunkah
Emperor
Yes, the AI penchant for sending its units swimming in the midst of combat has always puzzled me, but in particular for the fact that it will do so without any regard for the presence of enemy naval units. That couldn't be terribly hard to fix.
The thing is it always does this no matter the situation. It seems to me like they have the Boolean statement backwards. If "is there Enemy Navy within city borders" = "Yes" then attack Navy with nearest melee unit...