Convoy of towed ocean going cargo vessels and method for shipping across an ocean

A method for initiating shipping a cargo across an ocean from a port of origin located upstream from a mouth of a river, the method comprising:

• an uncoupled self propelling first cargo ship traveling upstream from the mouth of a river to the port of origin;
• loading the cargo onto the uncoupled first cargo ship at the port of origin, the loaded first cargo ship then traveling to the mouth of the river;
• coupling the first cargo ship with at least one other cargo ship and an ocean tug;
• the coupled cargo ships and ocean tug heading from the mouth of the river towards the ocean, during which time the first cargo ship receives control signals that contain navigational commands, and applies the received navigational commands to navigation implements of the first cargo ship;
• then uncoupling the first cargo ship from the other cargo ship;
• and
• then the first cargo ship continues receiving control signals that contain navigational commands, and applying the navigational commands to navigation implements of the first cargo ship.