Unmanned vessels currently cannot operate legally in international waters, as they do not meet the minimum crew requirements.

Also, with no crew aboard, the registered owner of the vessel will be on the hook to pay for any salvage operation that may be required to mitigate environmental damage or damage to the vessel. Also, tech-savvy pirates may find an un-crewed vessel to be easy pickings, with no one around to prevent boarding, disconnect of remote control, and disabling of tracking devices.

The technical challenges of making it possible are only the first obstacles to making it economically viable. Being able to enter ports and get maritime insurance is critical.

But if the kinks can be smoothed out, unmanned ship technology will almost certainly be moving goods from Shanghai to Long Beach soon after. Otherwise, only military groups will bother trying.