The Garmin bronze thru-hull mount transducer (Airmar B117) is an excellent choice for fiberglass and wood hulls this 8-pin 600 W narrow stem transducer has a depth of 800 to 1 200 ft; an operating frequency of 50 to 200 kHz; a beam width of 45 to 12 degrees; and a 0 to 7 degree deadrise.
