What’s this for?

[Quickstep192]

I’ve noticed this cleat on the forward end of the boom. Theres a sheave in the boom above the cleat and there’s a messenger that goes to the aft end of the boom where there’s another sheave. There’s no mention of it in the owners manual. 
 

Can anyone tell me what it’s for?

 

[silent bob]

Reefing Line!

 

[IMR]

Also sometimes used as an outgraber 

 

[Quickstep192]

So just how is this used to reef? 

 

[yoyo]

Looks like a messenger line where the 2nd reef line would go. 

Many boats will pull one or even both reef lines out and leave messengers in their place to reduce weight/windage/clutter for racing.

 

[ROADKILL666]

Reef

 

[Stiffler's Mom]

Flattening reef or reef. Used the harken to be able to shake it fast.

 

[Gouvernail]

Owner line.   Usually attached to shock cord inside. Owner is given job of “playing” that line from below deck in light winds. 

 

[full circle]

Flattening reef or reef. Used the harken to be able to shake it fast.

+1