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Mainsail Reefing Systems - Dual Line, Reef Procedure and Single Line, Reef Procedure.

The factory reefing configuration works OK but a crew has to go to the mast to set the first reef tack cringle on the ram's horn hook and then pull the clew line in.  The problem with this system is that the mainsail has to be dropped out of its track.  The trip to the mast must be coordinated with the helmsman.  Reefing is usually easier with crew on board but I wouldn't count on them if they are green horns.  You can only watch anxious crew dance around on the coach roof for so long, entertaining as they may be, before you have to do something and quick!  Sailing in heavy weather can humble a crew and sailing solo usually adds a few twists that you may not have thought of.  Staying within the safety of the cockpit helps to avoid risks, which means the reefing lines must be extended to the cockpit.  This demands that the system be well engineered and the process well thought through, unless you enjoy entertaining as well!   To determine which reefing system you want on your boat you have to decide where you want to control the lines lead to; cockpit, mid boom or mast.

Described here are two typical cockpit lead mainsail reefing systems that can be installed on an SJ23.  There are variations of these that tend to be complicated but I prefer a simple and functional system.  If you are unsure which one to choose, try using the system on a similar boat.  That way you can experience the pros and cons before you spend your hard earned cash or perforate your boom with unnecessary holes.  The biggest hurdle to overcome is not pulling in the reef, but releasing it.  That is why some people opt to keep the free ends of the reefing lines on the boom.   It has the least internal resistance, is the cheapest to install but requires you to crawl to the mast to adjust the lines.  I prefer to stay in the cockpit when I'm sailing solo which is why I lead the lines to the cockpit.  Having installed and used the single line system I can tell you that the dual line system works way better, which is why I mention it first.

DUAL LINE REEFING SYSTEM, (Separate Tack and Clew Lines for each Reef Point) - The biggest advantages of a dual line system is that it has the least internal friction and the tack and clew lines can be controlled independently, making it easier to use than the single line system.  The dual line system is depicted below, mainsail hoisted on the left and reefed on the right.  For the sake of simplicity the lines for the second reef are not shown but they are shown in bottom of the table below.  The clew block (marked A on the boom) is positioned so the reef line intersects the strain (reefed sail) at about 45⁰.  If the position of the SJ23 boom on the mast is fixed then the tack eyelet should be positioned on the mast, a few inches below the bottom of the boom.  This intersects the strain at about 60⁰ (reefed sail) with most of the force being upward along the luff.  The tack cringle will slide across the tack reef line when the boom swings, therefore it is OK to leave a bit of slack when the tack line is set.  A perfectly packed, efficient sail isn't required for a reef since there is too much wind anyway.  However, you should flatten the sail with foot tension as much as possible to reduce lift.

If you want to slide the SJ23 boom down the mast in heavy weather then the tack line fairleads must be installed on the boom instead of the mast.  In this case you will have to mount the fairleads as far forward on the boom as possible.  This configuration isn't that conducive to efficient reefing.  I far prefer the boom to be fixed with the fairleads mounted on the mast.  Your choice.

The lines of each reef should be colour coded to differentiate between reef 1 & 2.  Its a "good" thing to pull the correct one, the first!  For the same reason the rope clutches or cleats should be labelled (tack 1 / clew 1).  Of less significance is the colour of the mid tie down lines on the mainsail. 

CUNNINGHAM LINE - This mainsail flattening line is not shown in the drawing above because the drawing would become too cluttered.  The cunningham cringle is about 6" above the tack.  Look closely and you'll see it.  There are several ways to pull this cringle down to flatten the mainsail.  You could run a permanent line through it similar to a tack reefing line.  I prefer to slip a stainless tack hook (with line attached) through the cunningham cringle then pull it down and secure it around a cleat on the mast.  This extra tension flattens (depowers) the mainsail to match higher wind speed.  It is a useful technique for racing where a tenths of a knot may allow you to sail faster.  When cruising I seldom bother with the cunningham unless the wind blows not quite hard enough to reef.  The cunningham should be used in conjunction with matching outhaul tension to depower the main.  I do like to sail as fast as possible.

TACK LINES - As mentioned above you have to determine if the tack lines on your boat are to be attached to the mast (shown on diagram) or to the boom.  Regardless of which location, the dead end of a tack line is tied to an eye strap on one side, passes up through its respective cringle and down the opposite side through an eye strap and finally down to the turning blocks at the base of the mast if you want to terminate the line in the cockpit.  Since the majority of the sail cloth is bundled on top of the boom it is important to keep the lines away from the cloth so they slide freely.  This is why many people prefer to install the tack lines on the mast instead of the boom.  I transferred Panache's lines from the boom to the mast for the same reason.  Line length Tech Tip F03.

CLEW LINES - The dead end of each clew line is tied to the pin on the turning block installed on the boom.  From there it goes under the boom and up to its respective clew cringle, then back down through the same turning block on the boom.  This balances the load on this turning block and creates a 2:1 mechanical advantage for pulling sail cloth.  With the reefing line under the boom it also transfers some of the load to the boom.  Since there is limited space to install two turning blocks on the same side of the boom, the block for the second reef is installed on the opposite side.  The clew lines then go forward to turning blocks mounted on the front of the boom at the goose neck.  This greatly reduces the internal friction of the clew line since it can align with the direction of the pull to the deck block as the boom swings.  Line length Tech Tip F03.

I hope this explains the rational behind the dual line reefing system.  Each tack and clew line terminates in its respective rope clutch installed back at the cockpit.  The alternative is to install it on the boom.  Your choice.
 

HISTORY - In 2014 I replaced my single line reef system with a dual line system experimenting with some old 1/4" polyester line.  My single line system didn't work.  Once the tack cringle was down to the boom I couldn't pull the clew down due to too much friction in the system.

An SJ23 has very narrow deck space to install reefing lines lead back to the cockpit so the design is very particular.  I did a trial installation of my dual line system using the single line blocks and discovered it worked way better than the single line.  The first time I demonstrated the trial system I set and released both reefs in five minutes; would have been quicker if I didn't have to explain!  Click here for a description of how the system works.  Later I installed separate blocks and rope clutches for each line as shown in the photos below.  Line length is described in Tech Tip F03.

By 2019 my polyester reefing lines were getting old and difficult to release.  Ironically releasing a reef quickly is the test of a good system so it was time to replace the lines.  This time I chose 1/4" (6MM) line, green for reef 1 & red for reef 2 to match the green and red rope clutches.  While it is tempting to use 1/8" slippery single braid Dyneema line, it would just be my luck that I would slice my wet hands open when pulling it.  So I installed 1/4" (6MM) Dyneema which is the minimum size a person should handle without wearing sail gloves.  See Tech Tip F03.  Dyneema doesn't exhibit torque loading, making it perfect for all the right angle turns a reefing line has to go through.  When shaking out a reef I usually hoist the mainsail with the winch to pull the Dyneema lines through the deck hardware.  Sometimes the internal load is too much and pull the slack to the mast prior to hoisting the mainsail.

Unfortunately the 1/4" (6MM) Dyneema line with the slippery jacket creeps slightly through Panache's rope clutches so I thickened the line where it is gripped.  Where to bulk up the line and for how long was determined with the mast standing to make an accurate measurement.  Splicing a piece of 1/8" line inside another line is a clever technique that creates tapered ends that easily slide through a block.  I spliced it using a 1' length of coat hanger wire, a wrap of fibreglass tape, some coconut oil for a washable lubricant, and then zigzag stitched through both to make them as "one."  The result is smooth operation, minimal wear and when the thick portion is in the line clutch you know the sail cringle is down correctly.  https://www.berkeleypoint.com/learning/singlebraid.html.  There are two alternatives:

• Slip a braided jacket (sleeve) over the line and whip the ends to create a smooth transition for sliding through the blocks.  Then zigzag stitch through it to make it as "one" with the core.

• Replace or adjust the cam in the rope clutch to handle a thinner line.

NOTE - In my tests of using 1/8" Dyneema line to reef the mainsail I determined that it griped well in a dual or single cam cleat and around a rough finished deck cleat.  What a surprise since this small size line is the most difficult to grip.  It failed miserably over a polished cleat as I could easily pull 3 wraps of line off that cleat. 
 

PORT DECK LINES	STARBOARD DECK LINES
* It's best to view these photos from the bottom to top of this table from the perspective of standing in the cockpit.*  (Go to reefing procedure).
2010 - Each mounting hole for Panache's deck hardware is sealed with epoxy and the foot print is sealed with butyl rubber or Marine Goop. 2019 - Below are the photos of deck mounted reefing hardware using 6MM Dyneema line covered with a polyester jacket so they can be gripped by the             Easylock rope clutches at the cockpit. 2022 - The free end of the boom vang line was moved to a starboard rope clutch. 2025 - The free end of the boom topping lift was moved to a starboard rope clutch. NOTE 1 - By convention the mainsail halyards terminate on the starboard side and the jib halyards terminate on the port side.  Panache's lines were installed opposite by a previous owner and it was too difficult to switch them.  I've gotten used to it. NOTE 2 - Directing the reefing lines to the cockpit loads up the strain on the gooseneck.  Make sure it is in good condition.  See Tech Tip F20.  The alternative is to install cleats or rope clutches on the mast or boom.  But then you must go to the mast to reef, something I'd rather not do when sailing solo.
Fig 21 - Cockpit  view of port lines.	Fig 22 - Cockpit view of starboard lines.
Fig 19 - Tack line set for 2nd reef.  (Both lines should go through their eye for a neat set for either reef.  I do screw up now & then.  See Fig 13).	Fig 20 - Clew line set for 2nd reef.
Fig 17 - Port clew fitting for 1st reef.	Fig 18 - Starboard clew fitting for 2nd reef.
Fig 15 - PORT - Tack cringle for 1st reef.  The 2 reef lines are tucked in behind the mast where they are out of the air flow.	Fig 16 - STARBOARD - Tack cringle for 1st reef.  The 2 reef lines are tucked in behind the mast where they are out of the air flow.
Fig 13 - The port reef line eye straps are level with the goose neck to set the correct angle when the reef tack cringles are down on the boom.	Fig 14 - The starboard reef line eye strap is level with the gooseneck.  The 2 tack lines are quick to release & stored on the boom during the off season.  NOTE - In photos 13 & 14 there are a  lot of loose lines hanging around due to the mainsail being down on the boom.  They all get straightened out once the mainsail is hoisted.  When I have calm weather I'll retake the photos.  But you should also know what it looks like with the mainsail down.  This will do for now.
Fig 11 - The tack and clew reefing lines come from individual blocks at the mast base to minimize friction.  All blocks are spring loaded to keep the cheeks aligned when the lines are slack.  The foot of the mast is labelled to identify which line goes through each block during mast stepping.	Fig 12 - The halyards & topping lift lines go to individual blocks at the mast base to minimize friction.  All blocks are spring loaded to keep the cheeks aligned when the lines are slack.  The foot of the mast is labelled to identify which line goes through each block during mast stepping.  The block with the blue line is for the vang.
Fig 09 - The outside sheaves are doubled for the reef lines.  The tack reef lines are directed outside the hand rail due to narrow deck space aft.	Fig 10 - This inside sheave may be doubled in future to accommodate the boom topping lift line, like Fig 09.  But this block will do for now.
Fig 7 - These 2 deck fairleads organize the lines around the hand rail stub to protect  the gel coat from abrasion.	Fig 8 - This deck fairlead organizes the lines around the sliding hatch to protect the gel coat from abrasion.
Fig 5 - The black Easylock rope clutch is for the main halyard and divides the tack lines on the left from the clew lines on the right.  To make sense of this arrangement, the green clutches are for reef 1 & the red clutches are for reef 2.  With this configuration I simultaneously pull both tack lines and then both clew lines so reef 1 comes down while keeping reef 2 lines snug.  It is especially important to pull the two clew lines together so clew 2 doesn't snarl around the end of the boom.  However, clew 2 can be pulled in later when pointed upwind.  HINT - A really easy way to "push" a line through a rope clutch is to use a fid.	Fig 6 - The blue boom vang line is located in the cockpit where it is easy to see the effect it has on the mainsail shape.  Far superior than reaching forward under the vang where the mainsail is out of sight. - The red storm jib halyard spends its time hoisted to the top of the mast for less weight aloft.  A light line is attached to pull it down for use. The bitter end is coiled at the top of the cockpit halyard bag for quick deployment. - The green roller reef halyard is normally tensioned at ~50 pounds.  The bitter end is coiled at the bottom of the cockpit halyard bag. - The halyard bag is oh so comfortable to lean against.
Fig 3 - Two Easylock rope clutches are bolted together as a unit to make a neat, strong installation.  The 1/4" cross bolts are each secured with a nylock nut.  Love those #6  Lewmar winches with dual pawls and needle bearings.	Fig 4 - To terminate the boom topping lift at the cockpit I installed a quadruple rope clutch (2 double clutches bolted together using (4 x 1/4)" bolts with nylock nuts) for a 1/4" line.  Talk about convenient.  UPDATED
Fig 1 - This is a sketch of how reef 1 (lower) and reef 2 (upper) lines is run on Panache using separate tack and clew lines.  In this installation each reef point is ~3' deep and parallel to the boom.  The reef 2 line is usually omitted from many diagrams but for the sake of clarity I've shown both here.  Somehow the gurus expect you to figure this out!  Having said that, the lines on the port side of the sails are omitted since including them challenges the capability of my drawing software.  However, it is shown in the Harken diagrams at the top.  So there you go, guess I'm somewhat as guilty too. NOTE - Tack and clew lines are shown pointed up to simplify the drawing.	Fig 2 - What a sweet shape to the mainsail.  It shows how the reef lines stay close to the sail cloth for minimal drag.  There is a bit of slack in the reefing lines so they don't pull on the cringles to affect the sail shape.
PORT DECK LINES	STARBOARD DECK LINES

FOR THE NOVICE - You can't learn if you are afraid, so reduce the sail drive or sail area to where you are comfortable.  See SJ23 manual.  This gives you the time to analyze and get a feel for the boat, to learn how quickly it heels in a puff or at what heel angle it likes to sail.  A SJ23 should be heeled no further than 20⁰.  It's OK if it dips to 30⁰ though but is the time when you should hang on the mainsheet to quickly release a bit of it.  20⁰ heel can easily be judged while on the water by looking at an inner post on the pulpit; vertical = 20⁰

REEFING PROCEDURE - Prior to reducing sail area by reefing, you should flatten the mainsail by tensioning the outhaul and then tighten the luff.  Pulling down on the Cunningham as it is far more effective than tightening the halyard.  The boat will stand up better to the wind with flattened sails while maintaining speed.  If the wind blows harder, then reduce the heeling by spilling wind from the top of the sails by releasing the vang and/or the mainsheet.  Lastly reduce sail area to the first reef.  The usual reefing procedure for Panache's 2 line system is as follows: 

1. Snug up the boom topping lift to ensure minimal strain on the mainsail for reefing.  I usually sail with it loose.  (You do check the horizon every now and then don't you?).  Panache has a mechanical boom vang but I still snug up the topping lift as a backup.
2. Release the mainsheet to let the boom feather in the wind.  This relieves the stress on the cloth, slugs and lines.  Maintain speed with the jib.
3. Lower the mainsail with the tack reefing lines while letting the main halyard slide through your hand, working one against the other to maintain a bit of luff tension.  Stop when the tack cringle reaches the boom or the mark on the halyard reaches the rope clutch. 
   - Pull the second reef line along with the first to minimize the chance of a snag!
4. With the tack cringle just above the boom, lock the halyard clutch and tension the reef line hard.  This flattens the mainsail.
5. Pull the clew reef line till the cringle is down to the boom and adjust the tension along the foot to flatten the sail, then lock the rope clutch.
   - Pull the second reef line along with the first to minimize the chance of a snag!
6. If you expect to sail for a long time in this stronger wind, roll up the loose cloth and tie the intermediate lines to gather it.  If you tie around the boom, leave the lines slightly loose so as not to strain the mid sail cringles as they are seldom strong enough.  But this may flatten the foot a bit which should create an easier motion through the water with more speed.  Not all mainsails are equipped with these lines or require them.  You could also tie a short line around the boom through the tack and clew cringles to remove some strain from the reefing lines.
7. If you haven't done so, now is the time to pull in the second reef lines before they snag.
8. If the weather worsens set the second reef on top of the first, repeating steps 2 to 6.
9. If you want to set a third reef on your SJ23 (I don't envy your weather situation) use loose lines with reefing hooks on the end to pull down the third set of tack and clew cringles.  Best to set these in place right after you set the second reef and sail to the first hiding hole you can find.
   - Very few SJ23s have a third set of cringles.  While reefing hooks may be difficult to set on a rolling deck, installing a third set of permanent reefing lines will clutter up the mainsail for the majority of use during lighter winds.  Trade offs again.
10. As the weather improves, shake each reef out by releasing the reefing lines and pulling the halyard up to tension the luff.  Maintain headway with the jib to keep the boat moving in a comfortable motion through the lumpy water. 

Here are some extra tips you might find useful.

• Support the boom with the topping lift to prevent stretching the leech while the mainsail is reefed.  The support could prevent a tear in the mainsail.  This is something I usually do on Panache with the first reef and always do with the second reef due to the 8x1 mechanical advantage of my mainsheet. 
• Keep a reefing hook handy in case a line wears through.  Panache has 2 reefing hooks hanging in the companionway ready for use.  Each one has a 4' long 1/4" line spliced to it.
• I abandoned the single line system described below because it has too much internal friction with lines through the cringles.  I was never been able to set a reef properly and always had to hike to the mast to pull the reefing lines.  I averaged 15-30 minutes to set a reef, a bit less to release one.  Enough said.  I think the single line system sucks!

SEASON START - Each clew line is tied to the block pin on the opposite side of the boom.  From there the line goes under the boom, up to the cringle, down to the block and forward through the eyes to the blocks at the end of the boom.  From there they go down to the deck turning blocks, to end at the rope clutch at the cockpit. 
Each tack line has a loop spliced at the mast end to be secured to the eye strap on the mast with a shackle.  It then goes up through the mainsail cringles, down to the mast turning blocks, around the deck organizer to end at the rope clutch at the cockpit. 

WINTER STORAGE - At haul out time I pull the clew and tack reef lines out of the deck blocks and bundle them under the mainsail straps on the boom.  The intention is to keep the reef lines with the mainsail on the boom during winter.  In winter I store my full batten mainsail on the boom, wrapped in the mainsail cover with sail straps relaxed.  The loaded boom is spread over several cushions to make it easy on things.  At launch time I unbundle the reef lines from the boom and run them through the deck blocks to the rope clutches.  Straight forward organization that is quick to deploy at the ramp.

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SINGLE LINE REEFING SYSTEM, (One loooooong clew to tack to cockpit line) - A single reefing line is simpler to install but more difficult to operate on a pocket cruiser due to lots of internal friction if the line is lead back to the cockpit.  It is likely OK if the line is lead to the mast.  When a reef is set you end up with lots of line in the cockpit, which can be a nuisance but doable if you stuff it in a bag.  The first reef should be a different colour than the second reef and the rope clutch should be labelled to eliminate confusion when the hull is heeling too much.  The problem with this system is the internal friction through the cringles, blocks, and against the sail cloth bundled on the boom.  I was never able to pull all the reef line to fully lower the sail to the boom.  It always required a trip to the mast to fiddle with the lines or tuck cloth in.  Just the trip I was trying to avoid. 
If setting a reef line is difficult then releasing a reef is even more difficult, to the point of being dangerous because it takes so long.  Usually I climbed to the boom to pull the reef line out through the cringles and free up the line jammed against the cloth and inside the blocks.  There was a better than excellent chance that the loose line has snagged on something which is really frustrating.
On some boats it is impossible to achieve proper luff and foot tension using a single line.  I think a single line reefing system will work OK on a smaller sail or one with lighter cloth but not on an SJ23.  I wouldn't recommend it.

The usual reefing procedure for a single line system is as follows: 

1. Release the mainsheet and let it feather in the wind to relieve the stress on the cloth and lines.  Maintain some speed with the jib.
2. Snug up the boom topping lift, having previously attached it with the worsening weather.  (You do check the horizon every now and then?).  If you trust your mechanical boom vang you may dispense with this step.
3. Pull the mainsail down with the reefing line while letting the halyard slide through your hand.
   Work one line against the other to maintain some luff tension.  It really helps to mark the lines so you know where to stop.  
4. When the tack cringle is pulled down to the boom, cleat the reefing line.
5. To lower the clew to the boom you will have to pull the reef line by hand and pull the extra line through the tack cringle and cleat the line. I find that I can seldom flatten the sail sufficiently for the higher wind speed.
6. Tension the halyard to flatten the luff.
7. If you expect to sail for a long time in heavy weather, tie the intermediate lines around the boom to flatten the foot and distribute the strain.  It also helps to pack in the excess cloth.  Not all mainsails are equipped with these lines or require them.  This is one job that you have to climb on the cabin roof for.  It cannot be done from the cockpit but the boat will have easier motion with a reef set in.
8. Pull in the second reef lines to remove the slack and eliminate the possibility of a snag.
9. If the weather worsens further set the second reef on top of the first.  Repeat steps 2 to 7.  This time it will be next to impossible to pull the line past the bundled first reef.  I have always had to do this in the marina before I set out into rough weather. 
10. As the weather improves, shake each reef out by pulling the halyard against the reef lines to maintain luff tension.  Maintain headway to keep the boat moving in a comfortable motion through the lumpy water.  (This is when you have to watch for motion sickness).

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There are many variations of these two systems.  Some sailors will dispense with leading the lines to the cockpit, preferring to terminate them on the front of the boom or on the mast.  While this system works well, it necessitates going to the mast which may be difficult in rough water if you sail solo.  In this case you better have a tiller tamer, auto pilot or be very quick!  Years ago I used this technique on my previous boat but usually delayed the trip to the mast hoping that the wind would subside.  It almost never did!  
Yet another system involves terminating the tack and clew lines at the center of the boom.  Positioned here it is possible to reef the mainsail while standing in the relative safety of the companionway or sitting on the coach roof.  As appealing as this may seem, the boom must be hauled inboard over the cabin to reach it which could create excess heeling when sailing upwind.  If you have an Olympic gymnast on board this is merely a challenge! 
If you want to add a second "set of hands" for reefing, install some lazy jacks.  See Tech Tip F22 for Lazy Jacks. 

NOTE: I borrowed the diagrams from the nice folks at Harken.
 

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