Rigging a Quick-Release Opti Mainsheet

In search of awesome rigging upgrades for their Optis, Blockheads Jack Goggins and Chapman Petersen joined with professional rigger Olli Lubker for a trip to Harken World Headquarters one cold day in snowy Pewaukee, Wisconsin.

First on the list was upgrading Jack’s mainsheet to an interchangeable 4:1/3:1 “quick release” system. The goal of this system is to let you quickly switch from more to less purchase (or vice versa) without untying the line.  It is one of the more popular upgrades in the Opti class and can be accomplished in several ways using a variety of parts and rigging methods. While we totally encourage you to experiment and find new ways to rig your boat, we’ve chosen to focus on this simple, effective method.

Watch the video for a step-by-step walk-through of the project. Here is a rundown of the key pieces of hardware you will need:

1. Harken 40 mm Carbo fiddle block (Harken part #2655). This will mount to the boom using a trigger shackle (Pictured below).
   

   Harken 40mm Carbo Fiddle Block with Trigger Shackle

2. Trigger shackle: This piece enables the “quick release” feature of the system. A trigger shackle is a spring-loaded hook that easily opens and closes. You will install two trigger shackles in different locations:
   1. Attach the first trigger shackle to the 40 mm Carbo fiddle block that hangs off the boom. Chapman explains the reason for this later in the video.
   2. Use the second trigger shackle on the “deadend” of the mainsheet line (the opposite end from which you hold and trim). In most mainsheet systems, the deadend is tied off to a block or shackle. However, in this system the trigger shackle lets you quickly release the deadend and remove purchase. This is demonstrated in the video.
      

      Trigger Schackle

3. New mainsheet line. Prepare to either splice or tie-off a trigger shackle to the deadend of this line.
4. Mount a Harken 40 mm stand-up Carbo block (Harken part #2652 forward on the hull.
5. Mount a Harken 57 mm Carbo Ratchet block (Harken part #2135) aft on the hull.
   1. 38 mm eyestrap: double fastener (Harken part #074).
   2. 22 mm spring (Harken part #071).
6. Tie a short but easily accessible Spectra loop around the forward-most of the two blocks affixed to the hull. This loop is where you will hook the trigger shackle to create a 4:1 purchase. Release the shackle and it will get sucked up to the block mounted on the boom, reducing the mainsheet to a 3:1 purchase. (Loop pictured below)

• Bonus tip: Watch to the end of the video to learn why adding a second ring to the mainsheet bridle helps during light air tacks and gybes.