Christmas trees, autonomous ships & broccoli

I was recently asked to comment on unmanned ships and autonomous ships. To me, an unmanned ship is one with no people on board. Hence, we can equate it to a remote-controlled ship operated from ashore. With current developments in technology there are companies that already claim to do just that. On the other hand, autonomous ships, as the name suggests, among other things is required to be intelligent, self-sufficient, independent and more importantly without human interfere