where is the location of built in gps??

i was wondering.. in a fishfinder with built in gps, is the gps reciever built into the headunit or transducer?? if its inside the transducer, wouldn't it be difficult to pinpoint a waypoint because the trolling motor will rotate the transducer aswell??

Its in the head unit.

+1
If the GPS Receiver were in the transducer the signals from the GPS satellites would get blocked by the water.
Now where in the unit they are may vary by manufacturer and model. Typically Humminbird places them in the upper right side of the unit.