Reefs: How Many and How Deep

Sail Plan Orginal Mac scaled used sails 2.tcd

How many reefs should we have and where should they be positioned?

Generally, whenever this comes up the debate quickly centres on how many reefs are “best”. Two, three, or even four. But if you really think about it, that’s a backwards way to approach the decision. A better order is:

  1. What is the smallest amount of sail area we need for the type of boat we have and the sailing we plan to do?
  2. Only after we have answered that, can we think about how large we want each reduction to be (granularity).

  1. Six Reasons To Leave The Cockpit Often
  2. Don’t Forget About The Sails
  3. Your Mainsail Is Your Friend
  4. Hoisting the Mainsail Made Easy—Simplicity in Action
  5. Reefs: How Many and How Deep
  6. Reefing Made Easy
  7. Reefing From The Cockpit 2.0—Thinking Things Through
  8. Reefing Questions and Answers
  9. A Dangerous Myth about Reefing
  10. Mainsail Handling Made Easy with Lazyjacks
  11. Topping Lift Tips and a Hack
  12. 12 Reasons The Cutter Is A Great Offshore Voyaging Rig
  13. Cutter Rig—Should You Buy or Convert?
  14. Cutter Rig—Optimizing and/or Converting
  15. Cruising Rigs—Sloop, Cutter, or Solent?
  16. Sailboat Deck Layouts
  17. The Case For Roller-Furling Headsails
  18. UV Protection For Roller Furling Sails
  19. In-Mast, In-Boom, or Slab Reefing—Convenience and Reliability
  20. In-Mast, In-Boom, or Slab Reefing —Performance, Cost and Safety
  21. The Case For Hank On Headsails
  22. Making Life Easier—Roller Reefing/Furling
  23. Making Life Easier—Storm Jib
  24. Gennaker Furlers Come Of Age
  25. Swept-Back Spreaders—We Just Don’t Get It!
  26. Q&A: Staysail Stay: Roller Furling And Fixed Vs Hanks And Removable
  27. Rigid Vangs
  28. Rigging a Proper Preventer, Part 1
  29. Rigging a Proper Preventer—Part 2
  30. Amidships “Preventers”—A Bad Idea That Can Kill
  31. Keeping The Boom Under Control—Boom Brakes
  32. Downwind Sailing, Tips and Tricks
  33. Downwind Sailing—Poling Out The Jib
  34. Setting and Striking a Spinnaker Made Easy and Safe
  35. Ten Tips To Fix Weather Helm
  36. Running Rigging Recommendations—Part 1
  37. Running Rigging Recommendations—Part 2
  38. Two Dangerous Rigging Mistakes
  39. Rig Tuning, Part 1—Preparation
  40. Rig Tuning, Part 2—Understanding Rake and Bend
  41. Rig Tuning, Part 3—6 Steps to a Great Tune
  42. Rig Tuning, Part 4—Mast Blocking, Stay Tension, and Spreaders
  43. Rig Tuning, Part 5—Sailing Tune
  44. 12 Great Rigging Hacks
  45. 9 Tips To Make Unstepping a Sailboat Mast Easier
  46. Cruising Sailboat Spar Inspection
  47. Cruising Sailboat Standing Rigging Inspection
  48. Cruising Sailboat Running Rigging Inspection
  49. Cruising Sailboat Rig Wiring and Lighting Inspection
  50. Cruising Sailboat Roller Furler and Track Inspection
  51. Download Cruising Sailboat Rig Checklist
Subscribe
Notify of
52 Comments
Oldest
Newest
Inline Feedbacks
View all comments
Richard Dykiel

Another great post, just in time for Thanksgiving! So Thanks, and happy Thanksgiving!

Dick Stevenson

Dear John,
Just a very well put and argued article and I support all elements.
One word of advisement to all who go with a third (or quite deep) reef is to find some gnarly weather and practice with the deepest reef. Getting the tack positioned correctly is often hard as the amount of sail that collects at the gooseneck in deeper reefs is impressive. The temptation is to just pull the tack down on top of bunched up sailcloth. There is so much cloth with such deep reefs that the deep reef tack ends up to high away from the gooseneck and too far aft away from the mast. Positioning the tack neatly in preparation at the mooring, it is easy to get a compact sail bundle. Not so easy at sea and the wind is howling. The danger is (in the likely lousy conditions one will be working in) that the tack of the sail will reside high up and well aft on top of the bunched up sailcloth and, when the luff is tensioned, will then load (overload actually) the first car above the tack and in time, the car will rip away from the sail (this car will take loads that should be on the tack). Having reef lines marked ahead of time ensures good tack placement and the major load on the tack.
There are remedies in tack cringle placement that can be addressed at construction for deep reefs. A further help might be shock (bungee) cord between sail and car, a technique we have been living with these last 2 years with our new sail and liking a good deal. It also can’t hurt to take the tail of the reef line and, in a belt and braces manner, secure that tack forward around the mast. Then check it after tensioning the luff and sailing it for awhile.
My best, Dick Stevenson, s/v Alchemy

Keith Jones

Dick/John,
On our mainsail we have Antal sail slides and the slide stack is quite high on our mainsail. On the 3rd reef (deep) we can’t hook the tack reef cringle to the the rams head hook. So we had our sailmaker build a piece of webbing with a snap hook and sewn eye that: snaps onto reef cringle, runs around mast, goes through reef cringle on other side and the eye slips on reef hook at the boom. After setting the reef and hoisting the main, the webbing strap tightens up around the mast to secure the reef point and takes the load off the sail slide.

Keith, s/v Pearl

Conor

Super insightful design comments! I am having a 3rd reef built into our mainsail, so this is extremely relevant. Just to confirm, the luff reef cringle should be placed between slide cars, so that the cringle can be lowered as much as possible, toward the reefing hooks on the gooseneck, right?

Conor

You are a legend John! Thank you for the quick response. Our sailmaker had never heard of rocker before, while discussing the layout of the reefs, so now I am a bit concerned and now trying to research and explicitly describe all of the small details that I thought he would already be implementing. Thanks again!

Dick Stevenson

John, I have called what you described as earrings and used them for years to good effect. For the third reef where there is so much more cloth and boisterous conditions, I did get nervous about hurting myself when I would be wrestling the ring over the horn/hook. I worried I would get a hand/finger caught between ring and horn as I used effort to wrestle the ring down and over the horn. So I came up with an alternative that works for me: basically a pre-marked line to an un-used cleat that feels safer to use and pulls the cringle forward.
My best, Dick

Dick Stevenson

Hi John,
Having just re-read this article, I am impressed with all the embedded sensibleness. We also have been struck by how much earlier we reef offshore, but I attributed it to an offshore timdness/ wariness. What you are espousing may have to do with the tolerance you and Phyllis have for bashing about. On the other hand, many men have ruined a good sailing partner by bashing to wind. Aside from relationships, staying comfortable (as possible) is just good seamanship when (as is usually the case offshore), the end is not in sight. You are in it for the long haul. We always try to move at 2/3rds speed offshore- rarely is there a true reason for hurry. Along those lines, we try never to ask more than 75-80% of Alchemy’s sailing capacity. It is in that upper 20% where damage to the boat and injuries to person is most likely to occur.
My best, Dick Stevenson, s/v Alchemy

Marc Dacey

What Dick calls “offshore timdness/ wariness”, I call “seamanlike prudence”. When I say we intend to go around the world at 4 knots SOG, I am not so much making fun of our steel cutter’s sluggish sailing habits…it’s actually better than I expected in that regard…but in terms of preserving gear and avoiding wear by sailing in the first three-quarters of the boat’s maximums in hope of being capable should winds and weather require the last quarter.

Richard Dykiel

i actually have a question: on my first boat, a Catalina 30, I didn’t have a hook for the reef cringle, which disoriented me a bit in the beginning. I ended up tying a line beneath the gooseneck, run through the cringle, and cinch it to a cleat lower on the side of the mast. It worked for me pretty well in coastal cruising. What would be the drawbacks of this approach on bigger boats and offshore ?

Dick Stevenson

Richard, There should be nothing wrong with this as long as the tack gets in the correct place. An earring over a hook may be faster and a no brainier as far as tack placement. What you describe is close to what I use for my third reef.
Dick Stevenson, s/v Alchemy

Richard Dykiel

Thanks John and Dick. I was also told I could use a Cunningham for the reefing tack on my new boat (a PSC Dana 24). A snap shackle would allow hooking to any reef cringle and the pendant would be routed through a block located at or below the gooseneck, providing the correct downward and forward pull for the reef tack. I’m sorry if this is slightly off topic but would like to know your opinion on this system, which might also help resolving the problem of the third reef.

John V

Hello John,
I would really like to read a chapter on rig tuning. Another hot topic for many of us, I suspect. Will stay tuned for this one…

John V

Dick Stevenson

Richard, If I follow you correctly, you plan to use a system originally designed for the Cunningham of the mainsail: a block and tackle of somesort or a line through a block at the base of the mast, for each of your reefs (and the Cunningham). For me, I would start to worry about the law of un-intended consequences. The more I mess with tried and true methods, the more trouble I often get myself into. For example, most reef tacks are dead ended (fixed in place) while yours will be a line (or block and tackle) and/or a jam/cam cleat. If that cleat slips (when reefed) your mainsail will likely rip at the first car. There are enough PSC Danas out there to find a consensus on what works on these well designed and well understood boats. I would suggest some research in that direction might answer your question.
My best, Dick Stevenson, s/v Alchemy

Stedem Wood

Great wisdom in this post and in the comments. As part of the safe and conservative mindset described, let me add that to avoid chafing the reef line, I nearly always tied the clew in with a separate strap after pulling in the next reef. It’s an extra step, and you have to remember to untie it, but that is small effort compared to chafing through the reef line at an inopportune time or just damaging the reef line during a long sail with reef(s) tied in. .

That thought leads to a corollary, when you do things the same way EVERY time, you don’t forget things like untieing a reef strap.

Stedem Wood
M/V Atlantis

David Z

Normally the reef is most of the time calculated as % of P.
For a 3 reefs main you design the 1st reef at 12% of P, the 2nd at 25% and the third at 45%. Not all the designer use this rule, most prefer make 12%,24%,36%of P and when there are two reef only they normally use 15% of P for the fisrt and 30% for the second.
The trysail Area is calculated as less the 0.175xPxE, so less then the 17.5% of your main.

In our boat we have a reduction of area from 94 sqm to 36 sqm with 3 reef at 2.5,5.5 and 9m from boom. So we sail with the 38% .
This rule si reported in many old sail plan like S&S, Van de Stadt, etc etc

Patrick

Nice article John, as usual.
Having recently completed a 22,500 mile loop around the S. Pac. including more than 8,400 miles, much of it to weather, from NZ to Sitka, AK. I agree with all that you said about the priorities but would comment as follows regarding having only two reef points.

Our boat, a Cabo Rico 38, with a SA/D of 14.8 was setup with a very heavily built fully battened, loose footed main and with just two reefs. The sail was designed and built by Carol Hasse of Port Townsend Sails here in Puget Sound. One reef was at 60% sail area and the other at 40%. With all those miles under the keel we are very happy with this configuration. That sail with the 2nd reef set, and combined with a heavily built stays’l, was flown for days at a stretch on the legs north from NZ to AK. We spent many days sailing to weather in winds in the 30 knot range with our highest recorded gust being at 50k. We also carried a storm stays’l and came close to setting it once on the leg from NZ to Rarotonga in the S. Cooks where we dipped down to almost 40 degrees south in search of westerly winds, but in the end carried on with the stays’l instead.

I thought your point about the difference between sailing on inland waters and the open ocean was especially important. I can’t count the times when I’ve discussed when we reef, our sailing angles etc. with inshore sailors and they just don’t get it. The difference between sailing on the Chesapeake or in Puget Sound and the open ocean with its fully developed wave trains is something one must experience to understand. I’m guessing even your well worded and reasoned explanation won’t get the idea across to some. Waves aren’t water, but energy moving through water and the significance of that energy on the open ocean needs to be experienced to be understood.

In regards to adding a additional strap at the reef clew we found that by using a high modulus line like Warpspeed we had zero chafe after 22,500 miles. The slippery nature of the line plus lack of stretch where it wraps thru the grommet resulted our reefing lines being ready for the next passage with virtually no apparent wear evident. YMMV, but that worked very well for us.

Eivind Haugan

My X-50 from X-Yachts in Denmark appears to be outside the normal numbers for ocean cruisers. With a recut high clewed jib and full main my SA/Deplacement is around 23.0. That said I think that a 9 ft deep keel with a 10,000 lb lead bulb and a carbon spar that saved around 340 lb at an average height of 35 above water. So the boat might be quite tippy at first but has great stiffness when pressed in heavy weather.
My question is; do you believe that a setup with two reefs (approximately 45 % reduction with reef #2), a trysail on a separate track, and a cutter stay for hanked on storm jib or an undersized #4 in addition to a roller reefing 100 % jib, is a seaworthy setup. (There is additional sails for downwind sailing including a code 0 and three different sized asymmetrical spinnakers, but that will be for light weather use, and are leftover from my shorthanded racing days)
Have in mind that we plan to sail from Southern Norway down to Spain in the summer, then continue to the Canaries and onwards to the Caribbean in November. We will then cruise the Caribbean for six months before we take the chicken option and ship the boat back to England.

Eivind Haugan

Thank you for the answer.
We will be testing our setup with trysail and heavy weather or storm jib on the cutter stay before we leave. Earlier we have sailed in about 30 knots TWS with two reefs and a 100% jib, but probably with a more heavily loaded and more heel than we would be comfortable with on a longer passage. As I realize that we need to sail the boat at less stressful mode when we are out there for longer.
Looking forward to test the Harken switch track system that should allow us to have the trysail prepared well in advance of it’s use. Do you have any experience with the Harken switch track?
As regarding your comment on loads, we have well sized winches and deck gear that should help us. But I would also argue that a lighter boat with a high righting moment can use smaller sail area to maintain a reasonable pace, compared to a heavier boat with the same righting moment, and that we thus have less loads than many other 50-footers. (But then again we have our Southern Spars carbon rig setup with 16 metric tons on the mast jack, so there is plenty of loads involved)

Ronnie Ricca

John and others,

I’m getting a new main made and the local sailmaker, who I have sailed with, suggested a tri-sail and two reefs over the 3 reefs that the boat came with and what I originally chose. He would do either but told me to do a little research on this before making my final decision. His reasoning was that the thrid reef tack cringle will be so high above the ram horns that it will pull further aft and put stress on the harken track cars. And if he made a strop it would be so long that I guess it would fling around and be a pain to get when the weather is deteriorated. He’s not pushing the issue so he gets another sail, just letting me know and making me aware.

I’m trying to visualize MC and the other earlier posters versions of this webbing with eye, especially the ones that mentions also going around the front of the mast to prevent the sail from pulling aft. Is this webbing loose through the cringle with two eyes on either side or is the webbing sewn into the luff of the sail on one or both sides? Is it long, like say a 1.5-2′ (cringle to ram horns) when the halyard is tensioned? Do you need hardware on the mast to keep the line from sliding up or down?

I really would rather not have to deal with a main AND a tri-sail right now. Plus the additional cost of a second sail to be made and also a second car track is more than I was wanting to spend and waiting to pay for the tri-sail later leaves me with high aspect main with only two reefs.

If there is any pictures, better descriptions, or links that anyone could shine light on that would be excellent as I look to this site as one of my most valuable tools for information and advice. I wasn’t sure if this was the right page to comment on or the other article (https://www.morganscloud.com/2010/11/19/reefing-a-sailboat/) I’m just trying to get a better grasp on what solutions I can do so I can do the 3 reefs without issues.

Warmest regards,
Ronnie

Bill Attwood

Hi Ronnie
My experience, for what it’s worth.
My new main was really stiff and the third reef rings (sometimes called “spectacles”) were impossible to get on the horns. Reef 1 was easy, and reef 2 difficult but doable. My solution was to sew longer strops for reef 2 and 3, about 10 inches for reef 3 and 8 inches for reef 2. Hand sewing through tape is easy, and the strops can be replaced/shortened as the sail loses its initial stiffness. I notice no problem with the spectacles flailing around, but if I did, I would put a loop of thin bungee between the specs to shorten them when not in use. Another tip, from the website of the yacht Totem, is to add short Dyneema strops with aluminium rings to the clew cringles, and run the reefing lines through the rings. Less friction and eases the bunching of the sail at the clew.
Hope this is useful.
Regards,
Bill

Lee

Knowing I haven’t the experience of the other posters it’s with humility I write this post. Still we commute with the seasons from New England to Eastern Caribbean and I’ve been sailing for over 3 decades. I have a masthead solent sloop. Before passage rig an inner dyneema stay to take a storm jib and deploy the runners. Have three reefs in the main. The third reef and storm jib take us down to a good plan to 40-45 sustained. (In fact even in line squalls with gusts in the high 50s double reefed solent and triple reefed main has been fine. ) Beyond that the jsd would go out. We are careful and pay attention to our weather router, don’t sail when significant cycloidal systems are likely so have dealt with line squalls and one gale but not storms. I have a track for a storm trysail but due to also having a Dutchman don’t carry one as rigging it in a blow would be difficult. I see many boats forgoing the trysail in favor of a third reef. I have no intention of ever being in the southern ocean or sailing out of season. The two lines for the third reef are brought aft. The cringles are placed so shape is good. There are blocks on the sail so friction is minimal. We are careful so there is no twist in the lines and have no difficulty reefing. For this type of mom and pop sailing are we being foolish?
svhippocampus
Outbound 46

Lee

Knowing I haven’t the experience of the other posters it’s with humility I write this post. Still we commute with the seasons from New England to Eastern Caribbean and I’ve been sailing for over 3 decades. I have a masthead solent sloop. Before passage rig an inner dyneema stay to take a storm jib and deploy the runners. Have three reefs in the main. The third reef and storm jib take us down to a good plan to 40-45 sustained. (In fact even in line squalls with gusts in the high 50s double reefed solent and triple reefed main has been fine. ) Beyond that the jsd would go out. We are careful and pay attention to our weather router, don’t sail when significant cycloidal systems are likely so have dealt with line squalls and one gale but not storms. I have a track for a storm trysail but due to also having a Dutchman don’t carry one as rigging it in a blow would be difficult. I see many boats forgoing the trysail in favor of a third reef. I have no intention of ever being in the southern ocean or sailing out of season. The two lines for the third reef are brought aft. The cringles are placed so shape is good. There are blocks on the sail so friction is minimal. We are careful so there is no twist in the lines and have no difficulty reefing. For this type of mom and pop sailing are we being foolish?

Rob Gill

Hi Lee,
We make similar follow the sun voyages from NZ to the Pacific but do carry a trysail (it’s a Cat 1 requirement for offshore boats leaving NZ anyway), but here’s a few additional thoughts for consideration:
1) If our main sail splits or is damaged, we have a completely separate sail that can be rigged in addition to our jib or storm jib, to keep us balanced and sailing. Perhaps your boat sails well under headsail alone?
2) If you need to stay off a lee shore (and you have a long one), heaving-to can be a great option and we find the trysail gives us more control when trying to balance and stall out the boat. We find, even with three or four deep reefs our boat is hard to stop fore-reaching, but we can almost back the trysail with its low aspect ratio cut which seems to keep her more settled.
3) If we lose our mast we have the possibility to create a jury rig using the spinnaker pole and with our trysail, have a sail with the right dimensions to set (haven’t practised this though) !
Rob

Rob Gill

Hi John, Lee,
Two other secondary uses for our trysail that I could add:
1) As a parbuckle. With the foot strapped along the leeward side-rail and the head attached to a halyard to retrieve a MOB with suspected hypothermia, rolling the victim up the boat side horizontally. It would take time to rig, but could be vital where a vertical lift could kill the MOB (heart attack). Since our Trysail runs on a luff foil and there are no hanks to undo, it is always available and being lashed down by the mast offshore, doubly so.
2) As an emergency fothering sail, if the hull breach cannot be accessed or stemmed internally. The flat cut nature of the sail, sail shape and heavy duty cloth lend themselves to this application for any sail in our wardrobe, with the most realistic chance of success.
Cheers,
Rob

Justin Davey

KoHi John
Have you written an article about trysail track location and fastening to aluminum mast?
I am installing a dedicated trysail track on my Contessa 26, which already has 3rd reef in main. How does one determine the correct hoist height? I am using heavy aluminum u track and was considering rivets vs rivnuts. hesitant to tap threads because the extrusion thickness is lesser than big boats. Any thoughts?

Thanks
Justin Davey
Contessa 26 #331 Little Duck X
Lunenburg

Justin Davey

Thanks John. I have replied in the other thread.

Justin

Rob Ramsey

Hi John & yall. I have been thinking about when to reef. Having both furling on Genoa and main (in mast) I can choose any percentage but I need something to hold on to. My new genoa came with four dots on the foot to indicate four reefing points. I found that pretty handy. So my thinking is as follows:

1. I stick 4 ‘reefing dots’ (black Dacron stickers) on the foot of both sails. Reefing to these dots adapts the sail area to 75%, 50%, 36% and, finally, 25%. The dots are therefore at 13%, 29%, 40% and 50% of the footlength from the tack, creating these sail areas. So if the foot length is 50ft, the reefing dots would be at 6,5ft, 15ft, 20ft and 25ft from the tack.
2. Next I get a measure of the force of the wind. I don’t need true force, just some relative indicator. Knowing that force squares with speed – so a wind of 4kts carries a relative factor of 16 and a wind speed of 3kts carries a relative factor of 9. Easy to create a table with relative forces for wind speeds from 1 to 60kts. To make it easier to read I divide this factor by 100 and subtract ‘1’ and call it ‘force factor’. For my boat, a force factor of 0 (windspeeds up to 7kts) means hardly any sailing, which is why I subtract ‘1’.
3. Now I create a table with wind speed, force factor, sail area percentage and, finally, by multiplying force factor by sail area%, a number which indicates the force being put on boat and rig (call it ‘rig load’). Something like this:

Wind speed Force factor Sail area% Rig load
15 2 100% 2.0
24 6 75% 4.5
30 9 50% 4.5
36 13 36% 4.7
48 23 25% 5.8

Mind you, both ‘force factor’ and ‘rig load’ are not in kgs. Lbs. meters et cetera, they are purely relative, indicative numbers.

I still need to experiment a bit in real life situations but I have built a table for Close hauled, broad reaching and running (different apparent winds of course and it is the apparent wind speed that matters) and try to keep the Rig load at around 5 and under 6 (pretty conservative). That gives me reefing points at different wind speeds.

Using preferred rig load of 5 and a maximum of 6 is based on my personal experience but one could, of course, choose any other number.

Naturally this is just part of the story and it should not deter from proper seamanship. It just gives me, my wife and sailing guests a handle on reefing.

I would be very interested in any of your thoughts …

Rob Ramsey

Thanx for your kind words John. I would agree that sea state plays an important part but that could be catered for by lowering the acceptable rig load leading to more conservative reefing strategies.

And there’s no replacing ones gut. However, while we were out on the north sea two weeks ago while I slept the wind gradually built. When I woke up (rolled out of my bunk and saw that our port holes were under water), I was shocked to see us beating at well over 25 knots. She was having fun … I truly hope this system will help her to decide to wake me up for reefing – using a table on a sheet of paper, the anemometer and dots on the foot of the sails.

Also, not everyone understands that wind pressure goes up with the square of the wind speed. Some think that the difference between 21 an 27kts is the same as between 11 and 17. It is not and now I can explain it to others.

JIM HILDENBRAND

John, when considering reefing and which sail to reef first, my primary consideration has been balance, as indicated by weather helm or Lee helm. If I had too much Lee helm, I reef jib first and vice versa. The helm and conditions inform me which sail to reef first. Since mast placement vary by design, ketch vs sloop vs cutter, isn’t weather-Lee helm the simpler indicator of which sail to reef first versus assume main first always? I look forward to your thoughts and expertise!
Jim

JIM HILDENBRAND

John, oh, would you recommend having a messenger line permanently rigged between the 2nd and 3rd reef cringle to pull the sail down to the boom—-assuming most sailors are not rigged for 3 reef lines? Ideas on what kinda knots you would use? Cow hitch on 3rd cringle and bowline on 2nd, since bowline can be easily un-knotted,,or 2 half hitches?

Guess one would need a properly placed cleat on the boom to quickly tie off?

Devils always in the details! Thanks in advance for your advice.
Jim

Eric Pederson

Nice discussion and just the thing I have been thinking about. Almost all my sailing experience above 30 knots have in protected waters.

In figuring out the deepest reef point, I have been thinking that if I am “comfortable” sailing with full sails at 20 knots, then at 40 knots, to keep the wind force on the sails to that “comfortable” level, I need to reduce my sail area to a quarter (25%), which is the same as reducing the luff by 1/2. Is 25% overkill in your experience? This 25% (sail area) reef would be in lieu of a trysail. Thanks!