Dotted Circle Map Question
 

After sailing on the surface with the TC going, I had a "ship spotted" message. After checking out the map and clicking on the square "ship" it stated:

Time:
Type: Grenville Type Freighter
Course:
Speed:

My question is:

What does the dotted circle around the square or ship mean? Does that mean the ship has Radar?

In the past when I saw the dotted circle, it was only on enemy warships. This time it is on a Freighter!!

On merchants, it estimates the visual range of that vessel.

On escorts, DD's etc, you may get more than 1 dotted circle/semi-circle, this can indicate Radar coverage, Hydrophone & Visual range.

However, I must say that I assume them not to be acurate.;)

Thanks