Wahoo 109 Backing Plate w/Gasket - Anodized Aluminum

The Wahoo 109 Backing Plate with Gasket is an essential marine hardware component designed for through-hull installations where secure, watertight sealing is non-negotiable. Whether you're running saltwater outrigger systems, transducers, or other deck hardware, this backing plate serves as the foundation for reliable performance season after season. Built for anglers and boaters who understand that corrosion and leaks are the enemies of long-term reliability, this component prevents fasteners from pulling through fiberglass or aluminum and creates a compressed gasket seal that keeps saltwater out of your hull.

Manufactured from anodized aluminum, the Wahoo 109 Backing Plate resists corrosion in harsh marine environments where unprotected hardware fails quickly. The anodized finish provides a protective oxide layer that prevents galvanic corrosion when paired with stainless steel fasteners—a critical consideration for vessels operating in saltwater. The integrated gasket creates a watertight seal under bolt load, distributing clamping force evenly across the backing plate's 3 x 3-inch surface to prevent stress concentration and hull damage. Its compact 0.3-pound profile makes installation straightforward on both new builds and retrofit applications without adding unnecessary weight to your vessel.

Serious fishermen and cruisers upgrading transducers, tower mounts, or outrigger bases will appreciate the durability and proven track record Wahoo Industries backing plates deliver. Installation is straightforward: position the gasket-equipped backing plate on the interior side of the hull, align fasteners with your deck hardware, and torque securely—the gasket compresses to form a lasting seal. This backing plate works with standard metric or imperial fasteners and is compatible with most marine through-hull applications where a 3-inch footprint fits your installation envelope. For anglers who've experienced hull damage from inadequate backing or moisture intrusion, upgrading to this marine-grade solution represents insurance against costly repairs and downtime on the water.