2 or 3 reef points???

[aj676]

We are in process of rigging our 42' catamaran (weighs approx 16,000 lbs.) and have the option to add another reef point. The design currently includes 2 reefs, each 20% of sail area. We're looking for any real experience or the pros/cons of 2 vs. 3 reefs and what percentage each reef was in those cases.

Tiny bit of backstory: We bought this boat in 2016, sailed/motored it home and have spent 5 years rebuilding it. So we really don't have a lot of experience with sailing it in any 'weather'. It was a power boat this year but is back in the water. Next year we will be a proper sailboat again.

[GordMay]

Well, I don’t have an answer, but I do admire your ability to create complex problems.

If there are no plans to sail offshore, two reefs will be plenty.


The typical cruising mainsail configuration uses two reefs, that are normally placed at intervals of approximately 12% of the luff length [not sail area].

In fact, most sailors, who limit their sailing to local trips, don’t sail for extended periods in high winds. The only high wind they will see will be in localized squalls, when they will probably take the mainsail down completely.

A third reef is sometimes added for offshore work, again at another 12% of luff length (36%). Few boats, however, are set up with reef hardware for three reefs. The third reef will slightly decrease the overall durability of the sail (by adding weight to the leech), and necessitate hardware changes to the boom, to allow for a third reef line.

Another approach to the problem is to space two reefs at slightly deeper locations than normal, approximately 15% and 32% of the luff length. With offshore sailing in mind, deeper reefs make sense. Some of this decision is boat specific. Certain boats may need more mainsail, or balance particularly well with a 12% reef.

The struggle involved with moving from a second to a third reef is an indication that being more conservative, and taking away more area with each reef, is simpler and generally makes the most sense.

[Snore]

As a delivery guy, I sail cats “by the numbers”. Engineers designed the standing rigging for certain levels of loading/stress. Start by reviewing the design specs.

If she was designed for 3 reefs, build the sail that way. Better to have the reef, if needed, than to lose a rig.

[chris mac]

We have a cat of similar size and weight. We just had our new mainsail installed, we did opt for 3 reefs. In the last 2 years we used the 3rd reef once on the old sail so we decided the peace of mind was worth it.

[Joh.Ghurt]

I had the same discussion with the sailmaker and it seems, you have 2 variables:
How many reefing points you have and by ow much is the sail reefed at this. Another factor to consider is how much surface does a fully stowed mainsail have.

As I have a rather smallish main-sail on my cutter rig, in the end I went with 2 reefing points, where the first reef is around 25% reduction and the second reef is close to the 3rd reef at 50%. Another reefing point even deeper wasn't considered, as we were getting close to the sail-area of running bare-poles with the sail tied down.

For me, as my boat is no racer and I'm single-hand most of the time, being slightly underpowered with he first reef wasn't a big concern. This is compounded by being at the moment in the Western Mediterranean, where I usually reef down immediately to the second reef if the wind picks up.

This only to illustrate, that a lot depends on your boat, your cruising ground, your style.

[aj676]

Thank you for your responses! Although reefing to the numbers is optimal, this boat is not production so the numbers are not readily available. In addition, , we have redesigned the hulls, gone from a 11 stay fixed mast to a 3 stay rotating wing mast. We will need to come up with some numbers considering all factors but we’re more looking for that real world experience of what is necessary or not. Ie. Only using the third reef once in the lifespan of the sails. The percentage of each reef is also helpful! This is all helpful. We are also considering that ‘bare pole’ is still 70 ft.² of sail area on this mast.

[django37]

As catamarans do not reef by healing, you should be able to reef the sails yourself. I had a 3rd reef installed before we sailed round the world, -but with carefull planning we never had more than 30 knots of wind - before we came to the Med. So we have not yet used the 3rd reef

[sailingchiro]

Maybe you could have the third reef installed but not put the reefing line on until you know you will use it. Such as a major crossing. That is alot of line on the third reef that will be swinging aft of the sail. Just a thought.

[aj676]

Originally Posted by GordMay

Well, I don’t have an answer, but I do admire your ability to create complex problems.

If there are no plans to sail offshore, two reefs will be plenty.


The typical cruising mainsail configuration uses two reefs, that are normally placed at intervals of approximately 12% of the luff length [not sail area].

In fact, most sailors, who limit their sailing to local trips, don’t sail for extended periods in high winds. The only high wind they will see will be in localized squalls, when they will probably take the mainsail down completely.

A third reef is sometimes added for offshore work, again at another 12% of luff length (36%). Few boats, however, are set up with reef hardware for three reefs. The third reef will slightly decrease the overall durability of the sail (by adding weight to the leech), and necessitate hardware changes to the boom, to allow for a third reef line.

Another approach to the problem is to space two reefs at slightly deeper locations than normal, approximately 15% and 32% of the luff length. With offshore sailing in mind, deeper reefs make sense. Some of this decision is boat specific. Certain boats may need more mainsail, or balance particularly well with a 12% reef.

The struggle involved with moving from a second to a third reef is an indication that being more conservative, and taking away more area with each reef, is simpler and generally makes the most sense.

Yes, we certainly seem to be good at creating some nice complex problems. I'll have to double check with the sail maker (North) and see if it truly is 20% of sail area or luff. Good idea to look into the 3rd reef affecting durability. I really do like the idea of only 2 reefs for several reasons. We've got a little more time yet to ask additional questions and agonize some more.....

[aj676]

Originally Posted by django37

As catamarans do not reef by healing, you should be able to reef the sails yourself. I had a 3rd reef installed before we sailed round the world, -but with carefull planning we never had more than 30 knots of wind - before we came to the Med. So we have not yet used the 3rd reef

Careful planning and not getting into dicey weather is definitely our style, so that's good to know!

[DMCantor]

Sailing in the trade winds, in the Eastern Caribbean, we often use our 3rd reef, especially in times of "Christmas Winds" (which often extend well into January). Around the ends of islands, it is not unusual to see 40+kt gusts.


Our monohull is well balanced with the 3rd reef, and we really don't give up any speed when the winds are strong.

[beirutsailor]

A compromise would be to have the two reefing points on the sail, but not install the lines for the third reef, which are a nuisance. In a rare emergency, you can tie the sail down with short ropes.

[mindsofman]

Even with 4 reefs,,if that wind gets up to 40-50kts you'll
Wish you had another one..
ALWAYS go with safety in mind.

[john2445]

If "bare poles" for you is 70 sq ft, that's your 3rd reef. For me, probably my 2nd.

[Jammer]

Originally Posted by aj676

We are also considering that ‘bare pole’ is still 70 ft.² of sail area on this mast.

The usual goal of a third reef is to be able to maintain directional control.

Originally Posted by GordMay

The third reef will [...] necessitate hardware changes to the boom, to allow for a third reef line.

Many boats have a third reef available on the sail but do not ordinarily have it rigged for use. Instead, the lines for the second reef are relocated to the third reefing point when heavy weather is forecast. An alternative is more minimalistic rigging at the mast for the third reef.