Garmin AIRMAR B265LH Thru-Hull CHIRP Transducer (010-12379-20)

Introduction

The Garmin AIRMAR B265LH is a 1 kW dual-frequency CHIRP thru-hull transducer built for offshore and deep-water sonar performance. This transducer delivers accurate bottom tracking, fish detection, and structural detail in water depths reaching 3,000 feet—making it purpose-built for anglers who need reliable sonar data far from shore and in challenging marine conditions where single-frequency transducers fall short.

Key Features

• Dual-Frequency CHIRP Technology: Low-frequency range of 42–65 kHz for deep-water penetration combined with high-frequency range of 130–210 kHz for enhanced target definition and fish separation.
• Maximum Depth Capability: Rated for depths up to 3,000 feet, enabling effective sonar returns in offshore environments where standard transducers lose signal strength.
• 1 kW Power Output: Professional-grade 1,000-watt transmission provides strong sonar coverage and improved target detection across variable water conditions.
• Beamwidth Performance: Low-frequency beamwidth of 16°–25° paired with high-frequency beamwidth of 6°–10° creates a wider search pattern at depth while enabling precise target resolution in shallow water.
• Deadrise Installation Compatibility: Supports hull deadrise angles from 0°–20°, accommodating a broad range of vessel hull designs for proper transducer alignment.
• Thru-Hull Mounting Design: Permanently mounted through the vessel hull for long-term marine use without performance degradation from exposure to air or surface conditions.

Data Insights

The B265LH's dual-frequency architecture addresses the core limitation of single-frequency transducers in variable depth environments. The 42–65 kHz low-frequency channel penetrates beyond 3,000 feet while maintaining sufficient resolution for bottom structure mapping, while the 130–210 kHz high-frequency channel provides water column detail in the upper 500–800 feet, allowing simultaneous monitoring of bottom composition and suspended fish targets. This frequency separation enables anglers to identify subtle differences between hard bottom (rock, clay) and soft bottom (mud, sand) at depth, improving fishing location decisions and reducing unproductive search time. The narrow high-frequency beamwidth (6°–10°) produces the sharp target definition needed to distinguish individual fish from bait schools, while the wider low-frequency beamwidth (16°–25°) covers larger search areas at depth, balancing coverage with precision.

Usage Instructions

Install the B265LH transducer following the included AIRMAR and Garmin installation instructions, ensuring proper hull placement perpendicular to the waterline for accurate sonar operation. Connect the transducer to a compatible Garmin sonar system and configure sonar parameters based on your fishing environment—adjust gain settings and frequency selection to match water clarity, target species, and depth. Inspect the transducer and mounting hardware regularly for corrosion or loosening, particularly in saltwater environments, and verify that sonar readings match expected bottom depth before deploying into offshore conditions.

Design & Material

The B265LH features a robust conical housing and integrated sonar elements engineered to withstand prolonged saltwater exposure and the mechanical stress of high-speed vessel operation. Its compact bronze thru-hull fitting and precision CHIRP electronics ensure consistent performance across offshore fishing seasons, while the dual-frequency architecture integrates two independent sonar channels into a single installation point, reducing hull penetrations compared to separate low and high-frequency transducers.

• Premium 1 kW CHIRP architecture with dual independent frequency channels for simultaneous deep and shallow-water imaging.
• Low-frequency 42–65 kHz channel optimized for deep-water bottom penetration and structure detection beyond 2,000 feet.
• High-frequency 130–210 kHz channel designed for sharp target separation and detailed water column analysis in offshore conditions.
• Bronze thru-hull housing with marine-grade corrosion resistance for saltwater fishing applications and extended service life.
• Narrow high-frequency beamwidth (6°–10°) and wide low-frequency beamwidth (16°–25°) combination provides both precision targeting and broad search coverage.
• Compatible with 0°–20° hull deadrise angles, fitting V-hull, modified-V, and moderate-deadrise offshore fishing vessels without requiring custom mounting adapters.

Final Verdict

The Garmin AIRMAR B265LH Transducer is the right choice for serious offshore anglers who need professional-grade sonar performance in deep water. Its proven 1 kW dual-frequency CHIRP architecture, 3,000-foot depth capability, and combination of wide search coverage with precise target separation solve the real challenge of locating and identifying fish in offshore environments where accuracy directly impacts fishing success. If your fishing grounds extend beyond 500 feet of water or you require simultaneous bottom tracking and suspended fish detection in a single installation, the B265LH delivers the sonar clarity and reliability that offshore sportfishing demands.