Good to know. My primary concern, as a sailor, is a drone having no way of seeing me. Not all yachts have AIS, and radar can be notoriously unreliable in certain conditions. The drones in the article are only a touch smaller than my yacht, and quite possibly capable of sinking it in the event of a collision. And while it may be relatively straightforward to program stand on/give way behaviour, some of the other aspects of the the colregs, and good seamanship, such as responding to sound signals seem more intractable.