Airmar R109LHW 2kW CHIRP Thru-Hull Low/High-Wide Transducer

The R109LHW is the wide-beam variant of Airmar's 2kW thru-hull transducer family. The LHW designation stands for Low + High Wide, which calls out the defining feature of this element: the high-frequency band uses a constant 25-degree beamwidth across the entire 150-to-250 kHz frequency range rather than the narrow 4-to-8 degree beam most high-frequency transducers run. The wider beam gives you about twice the under-boat coverage at the high frequencies, which means you find more fish in the upper water column on a single pass over a stretch of water. For inshore work and for pelagic fishing where the targets are spread out at mid-depth, the wide-beam high element makes a meaningful difference compared to the narrow-beam alternatives.

The low-frequency element handles the deep-water side. CHIRP sweeping from 38 to 75 kHz with a 19-degree port/starboard beam and a 10-degree fore-aft beam (narrowing to 10 and 5 degrees at the upper end of the band). Maximum depth on the low band runs to 6,000 feet (1,829 meters), which is plenty for canyon-edge work and most offshore deep-drop applications. The high-wide band tops out at 500 feet (152 meters), which is the right depth range for what wide-beam high-frequency does best: fish-arch detection on inshore and shallow-water targets. Total usable bandwidth across both elements is 137 kHz, covering the popular 50, 68, and 200 kHz fishing frequencies plus everything in between. Modern CHIRP-capable sounder modules can sweep either band or both simultaneously based on what the operator wants to see.

The thru-hull mounting style is the standard offshore install. The transducer stem protrudes through the hull with the included fairing block on the outside hull face cleaning up water flow at speed. The fairing handles deadrise angles up to 22 degrees, which covers most modern sportfish and trawler hulls. For boats with deeper deadrise, a custom fairing block would be needed. Hull material is unusually flexible for a thru-hull: the R109LHW is compatible with all hull materials including fiberglass, aluminum, steel, and wood, which makes it usable on a wider range of commercial and recreational boats than most thru-hull transducers.

This SKU specifically is the bare-wire variant. The cable ends in unterminated wire pigtails rather than a manufacturer-specific connector. That's the right pick when you're hardwiring directly to a sounder module's input terminals or routing through a junction box mid-cable. For chartplotters with specific connector requirements, the connector-equipped variants of the same element are alternative SKUs. The fairing block is included with this SKU, which the connector-equipped variants may or may not include depending on configuration. The urethane potted housing handles long-term saltwater immersion without degradation, and the patented Xducer ID auto-detect technology lets compatible chartplotters automatically identify the transducer type and load the correct calibration tables without manual setup.

One important note from the manufacturer. This product cannot be returned to the original point of purchase, and warranty service goes through Airmar directly. The 33.3 pound (15.1 kg) weight requires structural hull integrity around the install point, which is standard on boats 30 feet and above. A marine electronics installer with thru-hull experience is the right person for the install, since the hole through the hull, the bedding details, and the fairing alignment all need to be done correctly. We can recommend an installer in your area for the bedding work, and we can spec the right sounder module pairing for the transducer before you order.

One more pattern worth knowing about choosing between LM (Low + Medium) and LHW (Low + High Wide) configurations of the same base transducer family. The Low+Medium variant is the right pick when most of your fishing is deeper than 200 feet and you want the medium-frequency element's resolution at canyon depths and on sea-mount tracking. The Low+High-Wide variant is the right pick when a meaningful portion of your fishing happens in the upper 500 feet of the water column and you want to cover more area on each pass to find pelagic fish or inshore schools. Both variants use the same low element for the deep-water side, so the difference comes down to what the high band buys you. For most sportfish operators who mix offshore deep-drop with inshore work, the LHW is the more versatile choice. For dedicated deep-water swordfish or sea-mount captains, the LM is the better tool.