Our P79 is a dual-frequency, depth only, in-hull transducer that easily adjusts to hull deadrise angles up to 22°.The P79 includes a plastic mounting base which is aligned to the centerline and secured inside the hull. Then it is filled with nontoxic antifreeze. The transducer is inserted into the base and adjusted for the proper deadrise offset, insuring the beam is shooting straight down for maximum echo returns. The coolant provides the best medium to transmit through the solid fiberglass and into the surrounding water. The major benefit of in-hull transducers is no protruding features on the exterior of the hull, making it the perfect choice for trailered or lifted boats. Designed for smaller boats up to 8 m (25′) with a solid fiberglass hull.