I just got one as a gift... made by Tamaya, with a curious clear "antena" Tried it out at the dock and it seems to work. Very directional, though.... it will certainly point at a boat almost perfectly. Has two modes, sound and needle mode. Needle mode seems to be a lot more sensitive.
My question is.... how do you make the first contact? It would not react to a radar without the device being pointed at it... maybe I was too far away?
Has any one used such a devise? The name of it is "Marine Check" radar detector by Tamaya.