How do your vessels comply with the international collision regulations? In particular, the requirement to 'at all times maintain a proper look-out by sight and hearing as well as by all available means appropriate in the prevailing circumstances and conditions'?
As it happens my full-time job is working on our COLREGS path planning and collision avoidance :) Our primary focus at the moment are the rules concerning standing on/giving way with respect to other vessels. Some of the other rules, such as the one you mention, aren't being handled at the moment. However, we do have active projects working on the vision side of things to help get us closer to full compliance.
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.