I have to agree with the above. Under sail its often hard to see in some directions especially with the now popular elevated helm stations. I once also noted truly bizarre behavior in the SFD where no one was manning the helm station of a large cat motoring. We were under sail and had to alter course to avoid a collision. We passed close astern to see the entire crew having a nice lunch! They seemed upset by the arm motions as we passed so close behind!
Oe thing I do as a courtesy is when on or near a potential collision course and the other boat has the right away I make a definitive move at a reasonable distance so the other boat is aware I have seen them and recognize they have the right of way. Usually I make a 20 degree course change. Very slight changes don’t let the other vessel know they have been seen.
.
