More on the subject of the yacht that was run down by a ship . This interesting insight into radar comes from Andrew Aldridge:

‘In my former career, I worked for Kelvin Hughes developing radars for commercial shipping. I have the following comments:

‘1: The size of the yacht is irrelevant. Any radar target that gets detected will “light up” at least one element of the radar’s range/azimuth grid. Except at close range, a target representing a yacht, oil drum or ship will appear the same size.

‘2: A steel yacht is a good radar target. A fibreglass yacht is not since fibreglass is more or less invisible to radar. Detection of a fibreglass yacht is normally achieved by reflections from engine or cooker. Masts are not good reflectors since they are curved and tend to reflect the radar pulse away from the receiver.

‘3: The height of the ship’s radar scanners extends the range at which targets low to the sea can be detected. Ships can detect yachts at moderate ranges but yachts only detect yachts at close range.

‘4: A radar is an analogue instrument at heart and requires continual tuning and adjustment for best performance.

‘5: The height of antennas on ships tends to worsen sea clutter close to the ship. A sea clutter control works by reducing the sensitivity at ranges close to the ship. Sensitivity reduction decreases with distance from the antenna. The consequence is that if close to a ship, smaller targets may disappear in the clutter or be withheld from display.

‘6: In my experience aboard both cruising yachts and commercial vessels, I have to say that commercial vessels generally have better situational awareness and expertise, contrary to popular opinion.’