This is something i always had as an idea ... In previous civ games the only ships you could lose in sea were trimeres & caravels. Now you cannot lose even those them since they cannot enter ocean squares at all.
But as we all know the sea is in true somewhat dangerous. thousands of ships have been lost at sea due to many reasons. Rough seas, dangerous waters etc etc.
So why not add a random chance that a ship travelling in the ocean or elsewhere ( not only a trimere or anything ancient, but also a modern ship ) can get lost at sea? Maybe even eliminate this threat with sattelites or something like that ( since now ships will have GPS guiding them )
I believe that the game is complete enough without this small add, but i would like to see it