Stack-type mainsail handling systems have become increasingly popular—and for good reason. They combine a mainsail cover with integrated lazy jacks, making it far easier to hoist, drop, and stow your sail than with a traditional setup.
The U-Stack is Ullman Sails’ take on this proven design. After years of studying other systems and refining our own ideas, we’ve developed what we believe is the most reliable and user-friendly mainsail stack system available. Each U-Stack is custom-built to match the exact specifications of your boat.
Key features of the Ullman Sails U-Stack include:
- Sewn with Gore Tenara thread—so it never needs to be re-stitched.
- Low-profile battens to minimize windage.
- Fitted center flaps and a full front flap for complete sail protection.
- Hidden zippers protected from UV exposure by cover flaps or “blind” seams.
- Chafe protection at all critical wear points, including the front and aft ends.
- Available in all Sunbrella colors, ensuring a perfect match with your existing canvas.
- Reinforced webbing attachment points for lazy jacks (unlike cheaper systems that tie directly to battens).
- Optional custom graphics for a personalized touch.
- Optional roll-away feature allowing the U-Stack to be neatly rolled down onto the boom for storage, with lazy jacks stowed away.