Abstract: Electric trolling apparatus is provided with a passage that protects a wire of a sonar unit and that also eliminates excess wire between a sonar transducer fastened to a trolling motor and a sonar control unit in a boat. The passage is defined by a tube inserted inside a trolling apparatus post and an electrical junction box secured to the post. One end of the tube protrudes through the trolling apparatus post and motor hub with a watertight connection. The tube second end emerges through the electrical junction box with another watertight connection. The wire passes through the tube and out its two ends without exposing the interiors of the post or junction box to water. The tube may be one long piece or two shorter pieces joined end-to-end with a watertight connection.