attwood Swivl-Eze Lock'N-Pin 1.77 Seat Base Plate — 9in Hard‑Anodized Aluminum Snap‑Lock

Attwood's SP-67904 Swivl-Eze Lock'N-Pin is a hard-anodized 9-inch aluminum snap-lock seat base plate that provides a corrosion-resistant, securely locking mounting point for boat seats.

This Swivl-Eze 1.77 Series seat base plate is designed as either a direct replacement or an additional seating anchor for fishing boats, pontoons, and cruisers. Built from hard-anodized aluminum, it resists saltwater corrosion and installs easily into a 2.5-inch diameter mounting hole. The base locks the seat into place in any swivel position, so you get reliable stability whether you’re casting, cruising, or docking. Attwood engineers these components with real-world marine testing to ensure durable performance in everyday boating conditions.

How does this seat base plate secure a boat seat so it won't wobble?

The Lock'N-Pin Snap-Lock design uses a positive locking mechanism that retains the seat post firmly once inserted and rotated into place. When locked, the base resists vertical and rotational movement so the seat stays steady during use. The metal-to-metal interface plus the engineered pin lock prevents slippage under load.

• Snap-lock system locks into any swivel position for stable seating
• Hard-anodized aluminum housing reduces flex and wear over time
• Compatible with standard 1.77-inch series posts and lock pins
• Designed for repeated insertions without losing retention strength

What are the installation requirements and how simple is setup?

Installation is straightforward and suited for DIY or professional fitment; the base requires a 2.5-inch diameter mounting hole in the deck or pedestal. Fasten the plate with appropriate marine-grade hardware and sealant to prevent leaks. No special tools or adhesives are necessary beyond basic hand tools and a marine sealant for a watertight installation.

• Mounting hole diameter: 2.5 inches
• Secure with stainless fasteners and marine sealant for longevity
• Compatible with standard swivel seat posts in the 1.77 series
• Quick replacement: remove old plate and swap in new unit

Why choose hard-anodized aluminum for a marine seat base?

Hard-anodized aluminum combines light weight with high corrosion resistance, which is critical for marine environments. The anodized surface increases scratch resistance and protects the alloy from electrolytic corrosion in saltwater conditions. This material choice balances durability with weight savings, benefiting handling and long-term reliability.

• Hard-anodized finish resists pitting and saltwater corrosion
• Aluminum construction keeps the unit lightweight yet strong
• Reduced maintenance compared with untreated metals
• Engineered for repeated exposure to marine elements and UV

Can this base be used for both replacement and new seating positions?

Yes—the SP-67904 is suitable as a replacement for old or damaged bases and as an additional mounting point when reconfiguring seating layouts. Its standard 9-inch size and industry-compatible dimensions make it a practical choice for retrofits and new installations. The durable design ensures a long service life whether used seasonally or year-round.

• Works as a direct replacement for many swivel seat systems
• Ideal for adding extra seating locations on pontoons or fishing boats
• 9-inch diameter fits common deck cutouts and pedestals
• Tested by Attwood for consistent fit and locking action

Who is this for? Boaters who need a dependable, low-maintenance seat base—angler-focused skippers, pontoon owners reconfiguring seating, and recreational cruisers replacing worn hardware—will find the Attwood SP-67904 Swivl-Eze Lock'N-Pin an efficient, corrosion-resistant solution. If you value a secure snap-lock hold, easy installation into a 2.5-inch hole, and the long-term benefits of hard-anodized aluminum, this 9-inch base plate meets practical marine demands without unnecessary complexity.