Garmin AIRMAR M265LH

Garmin AIRMAR M265LH

Garmin AIRMAR M265LH are a premier 1kW in-hull transducer designed for serious anglers who demand high-performance sonar without the need to drill through the hull.

At Morgan Marine, we understand that for many boat owners, the prospect of drilling a hole in the hull is a daunting one. The Garmin Airmar M265LH is the ultimate solution, offering professional-grade 1kW sonar performance in a convenient in-hull "tank" mount. This "CHIRP-ready" dual-band powerhouse is designed to deliver exceptional target separation and crisp imagery in both shallow and deep waters, reaching depths of up to 3,000 feet.

Whether you are targeting deep-water species or navigating complex coastal structures, the M265LH provides the clarity and detail required to find more fish. Installed inside the hull in a liquid-filled tank, it eliminates drag and prevents fouling, making it the perfect choice for high-speed powerboats, trailered vessels, and rigid-hulled inflatables (RIBs).

Garmin AIRMAR M265LH Key Features

Powerful 1kW CHIRP Performance: Delivering a full 1,000 Watts of power, this transducer penetrates deep into the water column to provide high-resolution imagery and superior bottom discrimination.

• Dual-Band Versatility:
  • Low CHIRP (42-65 kHz): Ideal for deep-water performance, allowing you to track the bottom and see targets at extreme depths (up to 914m / 3,000ft).
  • High CHIRP (130-210 kHz): Features a narrow beam (6° to 10°) to provide incredible detail on structure and pinpoint fish holding tight to the bottom in shallower waters (up to 304m / 1,000ft).
• No Hull Drilling Required: The in-hull design means the transducer is mounted inside a plastic tank that is bonded to the inner skin of your hull. This preserves the integrity of your vessel and is ideal for solid fiberglass hulls.
• Optimal Alignment: The included mounting tank can be cut to match your boat’s deadrise angle (up to 30°), ensuring the transducer beam is perfectly vertical for the most accurate readings.
• Superior Target Separation: By sweeping across a wide range of frequencies, CHIRP technology allows the M265LH to distinguish between baitfish and prized game fish with remarkable clarity.
• Xducer ID® Technology: Features Airmar’s patented technology, which automatically provides your Garmin chartplotter with the transducer’s specific configuration data for "plug-and-play" setup.

Technical Specifications:

• • Frequency: CHIRP Low (42-65 kHz) & CHIRP High (130-210 kHz)
  • Power Rating: 1 kW
  • Beamwidth: 16°–25° (Low) / 6°–10° (High)
  • Maximum Depth: 3,000 ft (Low) / 1,000 ft (High)
  • Depth Only: Provides highly accurate depth data.
  • Hull Compatibility: Suitable for solid fiberglass hulls only (not recommended for cored hulls).
  • Deadrise Angle: Supports 0° to 30° deadrise.

Morgan Marine Expert Tip: "The M265LH is our top recommendation for customers who want the power of a thru-hull transducer but prefer the safety and ease of an internal mount. It’s particularly effective on fast-moving hulls where transom mounts might suffer from turbulence."

In the Box:

• • Airmar M265LH Transducer
  • In-Hull Mounting Tank
  • Documentation/Installation Instructions

Note: Please ensure your hull is solid fiberglass before purchasing, as in-hull transducers will not function through cored or wood-sandwich hulls.

Garmin AIRMAR M265LH FAQs

Will this transducer work with my boat's hull?

The M265LH is an in-hull transducer, meaning it sits inside your boat. Crucially, it is designed only for solid fibreglass hulls. Because the sonar signal must travel through the hull, it will not work on boats with cored hulls (such as those with foam or balsa sandwiches), wood, steel, or aluminium hulls. If you aren't sure about your hull construction, please give us a ring at the yard and we can advise.

Do I need to drill any holes in my hull to install this?

No, and that is the beauty of this model! It is installed by bonding a plastic "tank" to the inside of your bilge and filling it with non-toxic anti-freeze (propylene glycol). The transducer is then bolted into the tank. This makes it a firm favourite for owners of high-performance boats who want to avoid the drag and risk associated with thru-hull fittings.

What is the benefit of the "LH" (Low/High) frequency?

This is a dual-band CHIRP transducer, giving you the best of both worlds:

• • Low Frequency (42-65 kHz): This is your "deep-water" setting. It penetrates deep into the water column (up to 3,000 feet) to find the bottom and large targets.
  • High Frequency (130-210 kHz): This provides a narrower beam (6° to 10°) for incredible detail in shallower water, allowing you to pick out individual fish arches and structure with pin-sharp clarity.

My boat has a steep deadrise; will the signal be pointing the wrong way?

Not at all. The M265LH comes with a mounting tank that is designed to be cut to the specific deadrise of your hull (up to 30°). This ensures the transducer remains perfectly level, sending its sonar beam straight down for accurate depth and target readings.

Does this transducer show water temperature?

Because the M265LH is mounted inside the hull, it does not provide an accurate sea surface temperature reading. If temperature is vital for your fishing, we recommend pairing this with a small, inexpensive NMEA 2000® temperature sensor or a separate transom-mount sensor.

Which Garmin units are compatible with the M265LH?

The M265LH is a 1kW powerhouse. It is directly compatible with Garmin’s professional-grade sonar modules, such as the GSD™ 26. It can also be used with the GSD™ 25 or certain GPSMAP® xsv series chartplotters, though you may require a 12-pin adapter cable depending on your specific head unit.

Is this suitable for high-speed use?

Yes, exceptionally so. Unlike transom-mount transducers that can suffer from "clean water" issues and turbulence at high speeds, the in-hull mount remains in constant contact with the hull’s inner skin. As long as the water flow beneath your hull is non-turbulent, you will get clear sonar returns even at high cruising speeds.

How difficult is the installation?

While it doesn’t require a hole through the boat, the installation must be precise. The tank must be bonded securely with epoxy to a flat, solid area of the bilge, and the tank must be cut at the correct angle. If you aren't comfortable doing this yourself, our service team at Morgan Marine can carry out the installation for you to ensure you get the best possible performance.