Chocks

What Are Marine Chocks?

Chocks are used to prevent dock or anchor lines from chafing as they pass over the rail of a boat — smooth, U-shaped devices that lines pass through from a cleat or Samson post to the dock. They can also be used with anchor lines to guide them over the bow. Whether you're securing a sailboat at a marina slip or mooring a cruiser overnight, chocks are a small but critical piece of deck hardware that protects both your lines and your hull.

Why Chocks Matter for Your Boat

Heavy-duty boat chocks play an important role in guiding and securing mooring lines, preventing damage to both the boat and the mooring structure. A chock is typically a metal fitting with a smooth surface, designed to prevent wear and tear on ropes as they pass through. Without a properly sized and positioned chock, mooring lines can saw against raw deck edges, leading to premature line failure and costly cosmetic damage to your boat's gelcoat or woodwork.

Mooring chocks distribute loads and protect mooring lines from excessive stress, safeguarding both the vessel and the mooring structure from potential damage caused by extreme forces. This load-distribution function becomes especially important in tidal anchorages or exposed slips where wind and current put sustained tension on dock lines throughout the day and night.

Types of Chocks to Know

Common styles include Skene chocks, often used at the bow to guide lines, and straight chocks. There are also closed chocks, which fully contain the line, as well as sunken or semi-sunken chocks that are designed to sit flush with the deck for a low profile, minimizing tripping hazards.

• Open / Skene Chocks: Open chocks have an open-ended horn, allowing easy access for attaching and detaching mooring lines.
• Closed Chocks: Closed chocks provide more security and are used in specific conditions where stability is paramount.
• Roller Chocks: Roller chocks are equipped with rollers to facilitate the smooth passage of lines, reducing wear and tear.

What to Look for When Buying Marine Chocks

316 marine-grade stainless steel is preferred for its corrosion resistance, strength, and durability. For boats regularly exposed to saltwater, material selection is especially important — fittings that corrode can stain decks, weaken under load, and create sharp edges that accelerate line chafe rather than prevent it. The size of chocks is based on the ship type and size, the proportional size of the lines, and the overall mooring and towing arrangement. Always match the chock opening to the diameter of your mooring lines for the best protection.

Proper maintenance and inspection of chocks are essential to prevent accidents and ensure the longevity of both the chocks and the lines they guide. Periodically check mounting hardware for signs of corrosion and confirm that the smooth bearing surfaces haven't developed burrs or rough spots that could accelerate line wear.

Top Brands in Marine Chocks

When it comes to trusted names in marine deck hardware, two brands stand out in this category. Perko is a long-established manufacturer of marine hardware with a reputation for quality fittings designed to withstand demanding marine environments. Their chock offerings reflect the same attention to finish and durability that has made them a staple aboard recreational and commercial vessels alike. Sea-Dog Line brings a broad selection of marine hardware to boaters at all levels, offering chocks in multiple styles and sizes to suit a wide range of docking and mooring configurations.