Garmin Plastic Thru-hull Mount Transducer with Depth & Temperature - Airmar 509LH
The in-hull version of the R509LH, this bare wire 2 to 3 kW transducer has a very narrow beam at both low and high frequencies for excellent deep water performance.
It has a depth of 10,000 ft; an operating frequency of 28 to 60 kHz and 130 to 210 kHz; a beamwidth of 9x23 degrees or 4 to 8 degrees; and a 0 to 22 degree deadrise.
Transducer kit comes with installation instructions. Follow the instructions carefully to avoid damaging your boat.
*Not the best choice for fishing in shallow water. Also not recommended for cored-hull vessels.