Some of the boats, it starts being installed July 1942, but progresses all the way into mid-1943, depending upon the boat. S-Boats do not get radar. It looks like October 1942 would be "average"... Also, "Visual" in the game on a clear, calm day in FotRSU might be as far away as 12.5k yards or more... I have a tendency to shy away from warships myself. Keep your head down...