I was just wondering if a car radar detector would alert you to a ship near by that had his radar turned on. I have used one for years while driving and they seem to work great. The best use I have had is while driving in Nebraska, completely flat land with every little town having a radar gun toting cop out hunting. It seems like with all the different bands a unit searches that it would work at sea. Just wondering, another safety tool. Very inexpensive also.