Unit 3 Underdeck Furler w7/8" Toggle (45 ft - 60 ft Boat Length)

Harken’s MKIV Underdeck Furling is the perfect solution for performance racers and cruisers who want an aerodynamic system with a minimal amount of equipment above deck. The drum is located beneath the deck, lowering the tack height for maximized sail area. The small outside drum diameter lets the unit fit inside narrow bows.

Ball bearings between the center hub and deck bearing provide for low-friction furling. The through-deck bearing minimizes water seepage into the underdeck compartment. The torque tube houses a full-length turnbuckle for optimal mast rake and tension adjustment.

The Unit 0 is a one-piece integrated deck bearing and line guard that is durable and corrosion resistant. It features an articulating ball joint, eliminating the universal joint and toggle to reduce weight and to simplify maintenance.
• Independent halyard and tack swivels furl sail center before head and tack for improved sail shape when reefed
• Lightweight aluminum halyard swivel saves weight aloft to reduce pitching and heeling
• Double-groove air foils for smooth sail handling and fast sail changes – even singlehanded
• Ball bearings between center hub and deck bearing, and main shaft reduce friction – so drum and halyard swivel turn freely under load
• Narrow diameter belowdeck drum fits narrow bows

Units 1, 2, and 3's aluminum line guard, torque tube, and swivels are deep-saturation hardcoat-anodized for no-fade UV stabilization and durability. The hardcoat-anodized line guard is urethane-coated for additional corrosion protection.

The torque tube houses a full-length turnbuckle for optimal mast rake and tension adjustment. A torque tube universal joint on Units 1, 2, and 3 provides a high-strength universal connection to allow ample headstay sag when sailing downwind.

Units 1 and larger have self-locking threaded height adjusters for a correct fit between the chainplate and deck.

• No height adjuster needed
• Furler and headstay are independent of each other, allowing flexible installation options
• Small outside drum diameter fits inside narrow bows