considering the current state of shipping, what exactly would these drone ships carry?

The Telegraph | Crewless 'drone ships' will be sailing the seas by 2020

Remote-controlled “drone ships” will be plying the sealanes without crews on board by the end of the decade, according to Rolls-Royce.

The FTSE 100 company best known for its aircraft engines is heading a consortium working to develop the technology needed for ships controlled from land bases, making them cheaper to run.   

“This is happening. It’s not a question of if, it’s a question of when,” said Oskar Levander, head of innovation for Rolls’s marine unit. “We will see a remote controlled ship in commercial use by the end of the decade.”

He predicted the system could turn ships into a seaborne version of car service Uber, with the potential to radically change the current shipping sector.

“Drone ships will allow the creation of new services, which will support existing players to make their businesses more efficient and enable new entrants with new business models to the sector, with a potentially similarly disruptive effect to that caused by Uber, Spotify and Airbnb in other industries.”