SeaSure 25mm Single Block w/Shackle

The SeaSure 25mm Single Block w/Shackle is a time-tested marine hardware component that delivers dependable line management for cruising sailors, commercial fishermen, and serious boaters who demand reliability in challenging conditions. This block excels in mainsheet systems, halyard assemblies, and general rigging applications where smooth pulley action and corrosion resistance are non-negotiable. Whether you're running a working fishing vessel or maintaining a cruiser that sees heavy seasonal use, this single block has proven itself across decades of real-world service on the water.

Built with marine-grade stainless steel side plates and rivets, the SeaSure 25mm Single Block resists salt-spray corrosion that degrades inferior hardware over time. The arnite plastic sheave is engineered for durability and minimal weight—critical factors when reducing windage aloft or avoiding system strain on smaller vessels. The integrated shackle attachment enables quick, secure connection to deck fittings, chainplates, or rail systems without requiring additional hardware. At just one pound, this block won't add unnecessary weight to your rig while maintaining the load-handling capacity expected from quality European marine engineering.

Experienced riggers favor the SeaSure 25mm range for both replacement work on aging standing rigging and new installations where budget meets performance. The plain bearing design operates quietly—a significant advantage on anchor watch or when stealth matters to commercial operators. Installation requires only a knife-edge sheave alignment and standard shackle sizing; no exotic tools or specialized knowledge needed. This block pairs seamlessly with standard marine rope diameters and integrates into existing tackle configurations, making it an ideal repair part for traditional gaff-rigged vessels, modern cruising sailboats, and working watercraft alike.