Mainsails – Furling vs. Standard

Do you drop or roll?  

Getting a furling or standard mainsail is one of the most debated topics in boat buying.  There’s a lot of good information out there and unfortunately the good information is often drowned out by misinformation on this topic, mostly fueled by folks who are disgruntled about one or the other (disgruntled folks tend to voice their opinions online more than content folks). 

This snippet is based on my experience as a guy who sells and fixes boats and who has worked in the charter industry for over 20 years.  Handling 20+ boats that go out on charter each week is like a accelerated course on what can go wrong on a boat.  I can’t dive too deep into the idiosyncrasies on this topic.  This relates to the average production cruiser and the average sailor.  Not catamarans, not performance boats and certainly not to the obsessive sail trimmer.

First, let’s dispel a few myths:

• “Standard mainsails are a lot of work to raise and to stow” – If you’re a cruiser, the best thing you can do to take the work out of raising your mainsail is to get an electric winch or an electric winch handle (the kind they sell with a battery pack).  Raising the sail is no longer an issue. At the very least, invest in a low-friction, ball-bearing, mast slide system that eliminates the need for muscle, even without an electric winch.  Equally as essential should be a mainsail containment system like Stack-Pack or Cradle Cover or Lazy Bag.  Whatever the brand name, this system, with a set of lazy jacks, will prevent you from having to scurry on deck to secure the main when the sail comes back down.  No, the main won’t fall perfectly into a containment bag but it will be 90% and that’s good enough to get into the marina and put it away properly without getting tossed around on deck.
• “Mast furling mainsails always jam” – They will jam if they aren’t used properly. Nine out of 10 jams that we’ve fixed for owners and charterers are from operator error.  Bad technique.  This is normally because the most experienced person on board is behind the helm and the newbies are taking orders.  A newbie (or even an experienced sailor with no furling mainsail experience) won’t know the nuances and technique.  So when a skipper calls me to say that the mainsail jammed, it’s almost always because of the crew.  That said, occasionally the system can fail without operator error and that’s pretty frustrating as well. But in almost every situation, the problems experienced on furling mainsails are rooted in something a human did somewhere along the line.  If it’s how the factory rigged the boat right from the start to the last time it was put away, etc. 
• “Furling mainsails take away from my boats performance” – First, consider what boat you have.  If it’s a cruiser, the furling main will have minimal impact on performance.  For comparison, changing from a fixed to a folding prop is a better performance enhancer than worrying about furling or standard mainsail.  When I see how people sail – their skill level, their ability to trim, how their boat is loaded down – often the furling mainsail is least detrimental to the overall performance.

These are the basic pros and cons.  In my experience, what people consider a pro or a con can be derived from either bad design or human error.

Standard Mainsail

• Pro – Straight forward.  Not a lot of moving parts to go wrong.  You know the sail will come down (although there are a few situations I’ve seen where it doesn’t but those are extreme examples).
• Pro – Better performance with better sail shape.  Able to use horizontal battens.
• Pro – Longevity.  You can sail with an old, blown-out full battened mainsail for eternity.  Sure, you’ll have poor performance, but it will still function. 
• Con – Limited reef points.  You usually have 1-3 choices for reefing.   
• Con – Might have to go on deck, to the mast, to reef or drop the sail.  Even if all reef lines are led back to the cockpit, you inevitably need to sort something out near the gooseneck or back towards the clew.
• Con – Difficult to reef so you might be reluctant to do it
• Con – Resale. For later model boats, it might take longer to sell a boat with a standard mainsail as most new or later model buyers are looking for furling mains.  For older boats, this isn’t an issue as people expect standard mains.
• Con – Cost.  They are more expensive than furling mainsails.
• Con – Extras.  You’ll want a few extras like a containment system (stack pack, lazy jacks, etc) and that can add to the expense.
• Con – Putting it on and taking it off seasonally and for servicing.  This takes time on a full battened main with all the mast slugs, battens, stack pack, lazy jacks, etc.

Furling Mast Mainsail

• Pro – easy to do when you do it correctly.  This justifies its own paragraph below.
• Pro – endless reef points.  I’ve found that when the wind pipes up, I roll the mainsail in until the boat becomes balanced.  Just keep rolling in until you find the sweet spot.
• Pro – easy to reef when you do it correctly.  And it’s all done in the cockpit.
• Pro – better resale for cruising boats
• Pro – cheaper than a full battened mainsail for replacement. And there are no extras for containment.
• Pro – you can leave it on all winter if you roll it in past the UV mark and then put a bag over the small clew corner that sticks out
• Con – the mechanism can break or jam.
• Con – the sail can jam coming in or out.
• Con – the sail can really, really jam coming in or out (so much that it justifies saying it again).  Regardless of whether it’s your fault, the crews fault or the mechanism just broke, a sail that’s stuck half in/out is very difficult to deal with. 
• Con – Limited longevity.  When it starts to become old and blown-out, you will get jams.  Best to replace it.  That said, I’ve seen 20 year old furling mainsails that still function but that’s rare.
• Con – Putting it on and taking it off.  If you don’t stow it in the mast for the winter, it’s tricky to get the head and the tack attached inside the mast.  Comparatively, taking a furling main on and off is like surgery – very precise, and brute force won’t fix it.  Vs a standard main that just has a lot of parts to wrestle. But do it once and you’ll come up with a method that is less frustrating for you.  

So What About…

Vertical Battens in Furling Mainsails? – These claim to give about 10% more sail area than a regular furling mainsail, but they can be problematic.  If the angle entering the mast isn’t next to perfect, it will be difficult.  Even if it’s perfect, you will encounter a “speed bump” when rolling in the sail.

Power Winches? – power winches will take the work out of any situation, but they will also power though a problem and cause damage.  They should never be used by an inexperienced person when raising, furling or unfurling your mainsail.  Power winches and inexperienced operators account for half of the furling issues I’ve encountered.  This is because if you were cranking by hand, you’d know pretty quickly when there’s resistance and you would stop before it becomes a problem.  Not the case when an inexperienced person holds their finger on the button of the power winch for a few seconds too long.

Boom Furling Mainsails? – for some reason these are not nearly as common as mast-furling mainsails.  And I have no idea why that is.  The advantage is that the sail can still act like a standard mainsail even if there are issues with the furling mechanism.  But from what I’ve seen, using a boom furling main has its own nuances and frustrations.  It’s pretty cool but not a fool-proof solution.

A few thoughts on jammed furling mainsails

• Control – like a furling genoa, you must maintain control on the two lines controlling the furling mainsail (furling line and the outhaul).  Never let a line go slack and run on its own.  Two common scenarios that cause problems:
  • Unfurling – One person pulls the furling line (unfurling) faster than the other person hauls it out.  This makes the sail unfurl in the mast, the wraps become loose and things get tight in there.
  • Furling – you tell your friend to get ready to furl in the main and they don’t realize the huge load on the outhaul line.  They maybe make one loop on the winch and then open the rope clutch.  That line will pop loose, same as a fully tensioned halyard would, and then the mainsail is flogging around.  But this actually isn’t the problem… the problem is when the crew just tries to roll the flogging sail up as quickly as possible.  Then the sail gets rolled away funky and probably won’t come back out.  Control and even pressure on the control lines is very important.
• Vang angles – the furling mainsail is cut for the factory setting of the boom angle.  It’s fine to adjust the vang when sailing but when furling out or furling in, the vang must be back at its proper angle, or the sail won’t squarely roll into the mast.  A simple solution is lining up a piece of tape on the vang line and tape mark on deck as this lets you know if your vang angle is correct.
• Halyard tension – if the main halyard is too tight, it can pinch the upper bearings and cause a problem rolling in and out. If the main halyard is too loose, the bag in the sail can also cause a problem.  The most common problem with the halyard becoming too loose is when you ask your inexperienced crew to do something and they mistakenly open the rope clutch for the main halyard instead of the main sheet or spin halyard (or whatever).  When they do this, the main halyard will only slacken a few inches, hardly enough to notice.  And this little mistake will cause a big problem when furling or unfurling the mainsail. The best way to prevent this is to secure the main halyard at the rope clutch so it can’t be accidentally released (zip tie the clutch shut or put a knot in the haly just forward of the clutch).

Overall, if you asked me what I would recommend (and you probably didn’t ask), I’d say…. either one is fine…  This may sound like a weak way of exiting this topic, but it really comes down to your personal preference.  If you have mobility issues, I would highly recommend a furling mainsail.  If you’re old-school and can’t get comfy with the furling idea, get a standard mainsail and a power winch. If you sail alone (and this can mean you sail with others but you’re the only one who’s sailing the boat), a furling mainsail might be better.  If your boat is on the sporty side and you’re one of those hyperactive sail trimmers, a standard mainsail might be best.  As you can see, it very much depends on how you sail.  And as long as you dispel the myths going into it, you can make a better decision for yourself.