If the public would tolerate them we could build unmanned cargo and tanker ships right now. Electronic engine management, GPS, and autopilots already mean ship crews are much smaller than they used to be and there is very little for the bridge crew to do between ports. They might need crews at the channel entrance to bring them into port and dock them but the crews could be taken off at the sea buoy on outgoing ships. Webcams and satellite links would allow the ship to be monitored and adjusted from centralized command centers on shore. One land based crew could monitor many ships at sea. I’d bet it’s coming but I’m not sure how long it’s going to take. Same thing is true of commercial airliners by the way. That may take longer because passengers want to know there is a qualified man/woman in the cockpit.
My sister and her husband have a 115’ boat they keep in a sheltered moorage in Seattle. We visited them on it in the waters around Juneau last year and I was being given the rundown of the Ships controls by the captain.
Basically they could have dialed in the waters in Elliot Bay (Seattle), hit “go”, and everyone could have gotten off the boat in the island waters near Juneau and met it in Seattle.
However, heaven help the boat or log that got in front of it.