I don't think most people appreciate how automated commercial vessels already are. The ship navigates autonomously from port to port. If you have a twenty man crew on a commercial vessel, they are split across two 12 hours shifts, you may only have one officer on the bridge during on watch, a few engineers below supervising the engines and performing preventative maintenance while underway, and able seamen will be doing the rounds checking nothing amiss such as loads moving etc. The crew are largely there to respond in the event of a crisis as commercial vessels are such an expensive asset.

I think it's better to think of the crew doing underway asset management than "sailing" the vessel.