Garmin Airmar B75L Bronze Thru-Hull Transducer, 40-75 kHz, 300W, 8-Pin, 0° Tilt, 0-7° Deadrise, Depth/Temp

Overview

The Garmin 010-11635-20 is a bronze thru-hull transducer that runs in the low CHIRP band (40-75 kHz) and outputs 300 W for depth and water-temperature data on compatible Garmin sonar electronics. It uses a 0° tilted element for 0-7° hull deadrise at the install point, with a beamwidth of about 32° to 21° (-3 dB).

The low-profile thru-hull housing sits flush to keep drag down and helps hold bottom at speed when the install location stays in solid water flow. Bronze thru-hulls are typically used on fiberglass and wood hulls; match the housing material to your hull and underwater metals to avoid corrosion issues.

Key features

• Low CHIRP 40-75 kHz band for strong bottom tracking in deeper water
• 300 W power rating
• 0° tilted element fits 0-7° hull deadrise at the mounting surface
• Beamwidth 32° to 21° (-3 dB) for coverage that stays useful as depth changes
• Provides depth and fast-response water-temperature sensing
• Garmin 8-pin connector for compatible Garmin sonar connections

Compatibility and fit

Plan this as a thru-hull installation through solid fiberglass or wood with enough flat area for the mushroom head to sit cleanly. The 0° tilt version is meant for near-flat running surfaces with 0-7° deadrise where it mounts; if the hull angle is steeper at that spot, the beam points off to the side and bottom readings can suffer.

It uses a Garmin 8-pin plug, so confirm your chartplotter, sounder module, or adapter cable is the Garmin 8-pin style before drilling the hull.

Installation and setup

Thru-hull transducers work best when they see water that stays free of bubbles and aeration. Mount it away from steps, strakes, intakes, and other fittings that can feed turbulence, and make sure you have bilge access for tightening and sealing.

Bed the housing with a marine sealant appropriate for below-the-waterline fittings, and re-check the nut and seal after the first few trips once everything has settled.

Electronics and sonar integration

Pair it with a CHIRP-capable Garmin sonar to use the 40-75 kHz band. In traditional sonar modes, the same transducer still supplies depth and temperature information.

Use on board

This is a good match for offshore anglers and cruisers who want low-frequency CHIRP coverage and prefer a flush thru-hull install over a transom mount that can ventilate at speed. It also suits boats that regularly run deeper coastal water where the low band holds bottom better than higher frequencies.

Maintenance and care

Keep marine growth off the face for consistent readings, and avoid hard scraping that can damage the sensing surface. During haul-out, inspect the bedding seal and the bronze body for any weeping or early corrosion so issues are caught before the next season.

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Customers are responsible for arranging and paying for return shipping unless the return is due to an error by Apollo Lighting or the item is verified as defective, damaged, or incorrect. Missing, damaged, defective, or incorrect items must be reported within 2 business days of delivery, and photos or other documentation may be required for review. If the issue is verified, Apollo Lighting may provide or reimburse return shipping and issue a replacement or refund depending on the circumstances. International customers are responsible for return shipping, duties, taxes, customs charges, brokerage fees, and other costs associated with an international return.

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For assistance, contact info@apollolighting.com or call +1 (954) 375-0100.

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Many products sold by Apollo Lighting include a manufacturer's warranty covering defects in materials or workmanship. Warranty terms vary by brand, product category, and model, so eligibility, coverage duration, exclusions, and available remedies are determined by the applicable manufacturer. We recommend reviewing the warranty information provided with your product before installation or use, especially for marine electronics, navigation equipment, lighting, electrical systems, pumps, safety equipment, and other specialized marine products.

If you need warranty service, the claim must follow the process established by the manufacturer, authorized service center, or designated warranty provider. You may be asked for proof of purchase, a serial number, product registration, photos, maintenance or installation records, or other documentation. Apollo Lighting does not determine or modify a manufacturer's warranty coverage or final claim decision, but we are happy to help provide purchase information and direct you to the appropriate manufacturer or warranty resource.

Keep your receipt, product documentation, serial number information, and original packaging when practical. Damage caused by normal wear, misuse, improper installation, insufficient maintenance, corrosion, impact, unauthorized modifications, electrical issues, or operation outside the manufacturer's specifications may not be covered. Warranty claims are separate from standard returns, so a product that has been installed, used, or exposed to marine conditions may no longer qualify for return while still remaining eligible for evaluation under the manufacturer's applicable warranty.

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