Steering a reasonably tight course is important to near by vessels plotting
your course intersecting theirs. I know of cases where a sail boat was being
steered by a Monitor windvane. The vane allowed the sail boat to wonder ~5
or so degrees due to light wind. The initial plot by a container ship showed
their course were diverging and without concern. In this case, the sail boat
skipper went below for scheduled radio contact (turned off radar because the
SSB interfered with it). 10 min. later the container ship took off his
bowsprit and about a foot of his bow.

The board of inquiry found neither vessel was maintaining a proper watch and
the plotting error was due to the fact the wind vane couldn't steer a tight
course.

Even from your own deck, you can be fooled about the this, as your boat
wonders on either side of your intended course.

Just my opinion FWIW.

Steve
s/v Good Intentions