Garmin AIRMAR B275LHW

Garmin AIRMAR B275LHW

Garmin AIRMAR B275LHW are a premium 1kW thru-hull transducer that offers the "best of both worlds." By combining a low-frequency CHIRP for deep-water performance with a unique High-Wide beam, this unit delivers twice the coverage under your boat compared to traditional high-frequency transducers.

The "Wide" element is the game-changer; with a constant 25° beam width across the entire high-frequency band, it creates crisp, large fish arches and superior resolution in the upper water column. Whether you are hunting pelagic species in deep blue water or working coastal reefs, the B275LHW provides the detail and breadth required to find more fish.

Built with a rugged bronze housing and supplied with a high-performance fairing block, this transducer is designed to maintain clear readings even at speeds exceeding 30 knots.

Garmin AIRMAR B275LHW Key Features

• Dual-Band CHIRP Power: Delivers 1kW of power across two channels. The Low frequency (42–65 kHz) excels in deep water down to 914m (3,000ft), while the High-Wide frequency (150–250 kHz) provides incredible detail in shallower depths.
• Constant 25° Wide Beam: Unlike standard transducers that narrow as frequency increases, the "Wide" version maintains a fixed 25° beam. This provides massive coverage for detecting fish in the upper water column—perfect for pelagic fishing.
• Superior Target Separation: High-wide frequency delivery ensures you can distinguish between baitfish and larger predators, providing the clearest return images available on your Garmin display.
• High-Speed Performance: The included High-Performance Fairing block ensures smooth water flow over the transducer face, allowing for accurate sonar readings at speeds over 30 knots (34 MPH).
• Comprehensive Data: Integrated high-accuracy depth and fast-response water temperature sensors.
• Robust Construction: Features a durable bronze housing suitable for fibreglass or wood hulls.
• Plug & Play Compatibility:  Equipped with a Garmin 12-pin connector for seamless integration with Garmin GSD™ 25 sonar modules and GPSMAP® xsv series chartplotters.

Technical Specifications:

• Frequency: Low (42-65 kHz) & High-Wide (150-250 kHz)
• Power: 1kW
• Beamwidth: 25° (High-Wide) / 16° to 25° (Low)
• Maximum Depth: 3,000ft (Low) / 500ft (High-Wide)
• Mounting: Thru-hull with Fairing Block
• Hull Dead-rise: Up to 20° with fairing

Morgan Marine Expert Tip: This is our "top-pick" transducer for offshore fishermen who want to see more water. The wide beam doesn't just show more fish; it shows them with much larger, more defined arches that are easier to spot at a glance.

Garmin AIRMAR B275LHW FAQs

What does the ‘W’ in B275LHW actually stand for?

The ‘W’ stands for Wide. Unlike traditional transducers that have a narrow beam (often narrowing further as you increase frequency), the B275LHW maintains a constant 25-degree beamwidth across the entire high-frequency band. This means you get much more coverage under the boat—up to double the area of a standard high-frequency transducer—making it far easier to spot fish arches in the upper water column.

What kind of depths can I expect to reach with this transducer?

This is a dual-channel 1kW powerhouse.

• • Low Frequency (42-65 kHz): Designed for deep-water performance, it can track the bottom down to roughly 914 metres (3,000 feet).
  • High-Wide Frequency (150-250 kHz): Optimised for superior resolution and target separation in shallower depths, effective down to approximately 152 metres (500 feet).

Is my boat suitable for a thru-hull bronze transducer?

The B275LHW is a bronze thru-hull fitting, which is ideal for fibreglass or wooden hulls.

Important: We do not recommend installing bronze transducers in aluminium or steel hulls, as this can lead to galvanic corrosion which will damage your hull. For metal boats, please speak to us about stainless steel alternatives.

Size: This unit is typically recommended for vessels of 8 metres (25 feet) and above.

My hull has a significant deadrise; will this transducer still work?

Yes. The B275LHW comes with a High-Performance Fairing Block. When properly cut to the angle of your hull, this allows the transducer to sit vertically for an accurate beam. It can accommodate deadrise angles of up to 20 degrees. The fairing also ensures "clean" water flow over the transducer face, allowing for clear sonar returns even at speeds over 30 knots.

Which Garmin chartplotters is this compatible with?

This version of the B275LHW typically features a Garmin 12-pin connector. It is designed to plug directly into "xsv" series units (like the GPSMAP 1223xsv or 8400 series) or sonar black boxes like the GSD 25. If you are unsure about your specific head unit's compatibility, give the team at Morgan Marine a call and we can verify it for you.

What’s the advantage of "CHIRP" in this model?

Traditional sonar sends one single frequency at a time. CHIRP (Compressed High-Intensity Radiated Pulse) sweeps through a range of frequencies. This results in much higher resolution, better target separation (distinguishing between individual fish in a bait ball), and significantly less "clutter" on your screen.

Does it provide water temperature?

Yes, the B275LHW includes a highly sensitive, fast-response water temperature sensor alongside its depth-sensing capabilities. This is vital for finding those temperature breaks where predatory fish often congregate.

How difficult is the installation?

As this requires a 30mm hole to be drilled through your hull and the precise cutting of a fairing block, we recommend professional installation. If you’re a confident DIYer, the kit includes the fairing block and mounting hardware, but getting the orientation perfect is crucial for performance at speed.

Morgan Marine Expert Tip: "If you're fishing in the English Channel or around the UK coast for species like Bass or Mackerel in the top 50 metres, the 'Wide' beam on this unit is a game-changer. You’ll see fish that narrow-beam transducers simply miss because they aren't directly under the keel."

Still have questions?

Pop into our showroom or contact the Morgan Marine team today. We’re here to ensure you get the right setup for your boat and your fishing style.