What is the typical operating range of Automatic Identification Systems (AIS) at sea?

Correct Answer: Option A — 20-25 nm

AIS operates in the VHF maritime band, which is primarily line-of-sight. Under normal atmospheric conditions, the typical effective range for ship-to-ship AIS communication is approximately 20 to 25 nautical miles, depending on antenna height and the power output of the transponder unit installed on the vessel.