Airmar B265LM - Bronze through-hull 1kW CHIRP transducer (42-65kHz/85-135kHz) with fairing block + temperature – (bare wires)

The Airmar B265LM is a 1 kW bronze through-hull transducer using CHIRP technology. It operates on two frequency bands, low (42–65 kHz) and medium (85–135 kHz), and includes a temperature sensor. Designed for mid to deep-water fishing, it provides precise target separation and bottom discrimination.

The Airmar B265LM transducer uses CHIRP (Compressed High-Intensity Radiated Pulse) dual-band technology. This technology enables precise target separation and seabed discrimination, delivering higher resolution and detail compared to fixed-frequency transducers.

The B265LM transducer operates on two distinct frequency bands:

A low frequency range from 42 to 65 kHz.A mid-frequency range from 85 to 135 kHz.These two bands combined provide a total CHIRP capability of 73 kHz.

The Airmar B265LM transducer is optimized for different depths depending on the frequency band used:

The low-frequency band (42 to 65 kHz) is designed for depths up to 914 m (3,000 ft). The mid-frequency band (85 to 135 kHz) is effective for maximum depths of 457 m (1,500 ft).

The Airmar B265LM transducer has a transmit power of 1 kW.

Yes, the Airmar B265LM transducer is equipped with an integrated water temperature sensor.

The Airmar B265LM transducer housing is made of bronze.

The B265LM transducer offers different beam angles depending on the frequency band:

The low-frequency band (42 to 65 kHz) has a beam ranging from 25° to 16°. The mid-frequency band (85 to 135 kHz) has a wider beam, ranging from 16° to 11°.

Yes, the application of an antifouling paint such as Foulfree is certified by Airmar and does not affect the transducer’s performance. This type of coating is non-toxic, durable (up to two years), and prevents marine organisms from adhering.

The Airmar B265LM transducer is supplied with bare wires, meaning the transducer cable is not terminated with a specific connector and will need to be wired according to the requirements of the compatible sonar device.

The Airmar B265LM transducer, being made of bronze, is recommended for fiberglass or wooden hulls only.

No, it is critical never to mount a bronze transducer on a metal hull, as this would cause electrolytic corrosion. The Airmar B265LM transducer is recommended for fiberglass or wooden hulls.

No, a metallic transducer (such as the B265LM in bronze) must never be installed on a boat with a positive ground system.

The Airmar B265LM transducer is a thru-hull type with a fairing. It is installed entirely outside the hull, with a hole drilled for the cable. The active face and sides of the transducer are submerged in water.

To install the Airmar B265LM transducer, a 33 mm or 1-5/16" hole is required for the transducer to pass through. A pilot hole of 3 mm or 1/8" must be drilled first.

Use of a fairing is highly recommended if the hull deadrise angle exceeds 10°. The fairing aligns the sonar beam straight downward by mounting the transducer parallel to the water surface and ensures clean water flow under the transducer face.

Installing the anti-rotation bolt is mandatory when securing the depth sounder shoe. This bolt firmly holds the shoe in place and prevents it from rotating when the boat is underway, avoiding violent movements and loss of directional control.

For optimal performance, the transducer must be installed in an area where the water flow under the hull is smooth, with minimal bubbles and turbulence, especially at high speed. The transducer must remain continuously submerged, and its beam must not be obstructed by the keel or propeller shafts. It is recommended to install it at least 300 mm (1 foot) away from a keel and clear of interference sources such as propellers or water intakes.

CHIRP sounders generate more heat than traditional sounders. To prevent overheating and failure of the sounder, it is crucial to always use it submerged in water. Never operate the sounder in open air. Installation must comply with the manufacturer's instructions to ensure adequate thermal dissipation.

Yes, applying water-based antifouling paint is mandatory in saltwater to maintain the transducer's performance by preventing marine growth. It is essential to use paint compatible with transducers and to never use harsh solvents.