[propbeanie]

The Japanese radar in the game is nerfed, to put it politely. Some airplanes / ships are entirely too strong, and on others, non-existent. There is also the "chance" factor in the game, where something might have a 50/50 chance of detecting you, and the game's choice is usually it detects you. The dice have rounded corners, and are weighted...

There are circles associated with ships for radar, visual, hydrophone and sonar on the escorts (if they have the gear), from outside to the inside. The merchants might only have the visual. Some of the larger warships might not have the sonar, etc. Those depend upon the sns file for each ship, and what it loads by date.