Anno 2070 Deep Ocean underwater Safe transportation. (Anno 2070)

The game certainly is not new but the time transcripts ) 3 day play.. came to submarines, and I have a question how do underwater routes? if he dipped her under the water and put in the route, the submarine POPs up automatically.. tried to change warehouses all useless in the Internet and can't find info on this matter.. ( Tell me who knows I would be grateful.