Raymarine Fairing Block, For HV-300TH Thru-Hull Transducer

Overview

The Raymarine R70741 is a fairing block for the Raymarine HV-300TH through-hull transducer. It is used as part of the transducer mounting arrangement to help the HV-300TH sit correctly against the hull and maintain a cleaner water flow across the sonar face.

This is a non-electrical mounting accessory, so there are no voltage, network, or display connections to match. The fit decision is mainly about confirming that the boat uses the Raymarine HV-300TH transducer and that the through-hull location is suitable for that installation. The HV-300TH through-hull transducer is used in installations with hull deadrise angles from 0 to 25 degrees.

For boats that rely on sonar while fishing, cruising, or running in shallow-to-medium depths, a proper fairing setup matters. A damaged, missing, or poorly fitted block can affect how the transducer meets the water, which may lead to less consistent bottom tracking or imaging at speed.

Key features

• Made for the Raymarine HV-300TH through-hull transducer, keeping the mounting hardware matched to the transducer body.
• Supports proper through-hull transducer alignment on hulls within the HV-300TH installation range of 0 to 25 degrees deadrise.
• Helps the transducer face work in cleaner water flow, which is important for steady sonar readings underway.
• Non-electrical mounting part with no NMEA, RayNet, power, or display wiring to configure.
• Useful as a service or replacement part when the original fairing block is damaged, missing, or being refreshed during a transducer installation.

Compatibility and fit

This fairing block is for the Raymarine HV-300TH through-hull transducer. It should not be treated as a universal transducer mount, since the shape and fit are tied to that specific transducer installation.

Before ordering, match the transducer model on the boat to the HV-300TH and check the hull location, deadrise, and available interior clearance. Through-hull sonar installations should be placed where the transducer can stay in clean, aeration-free water and away from turbulence caused by strakes, thru-hulls, steps, or running gear.

Installation and setup

Installation normally takes place during a haul-out or while the boat is safely out of the water. The block must sit correctly against the hull and transducer assembly, with the transducer oriented for a clear view below and to the sides as required by the HV-300TH system.

Use suitable marine sealant and follow the transducer installation process for hull preparation, tightening, and leak checks. After launch, inspect the area for water ingress and confirm sonar operation at low speed before relying on readings at cruising speed.

Use cases on board

This part is a good match for owners, installers, and service yards working on a Raymarine HV-300TH through-hull sonar setup. It is especially relevant when maintaining fishfinder performance on fishing boats, coastal cruisers, and mixed-use powerboats where a secure, correctly aligned through-hull transducer is part of the electronics system.