Single Vs Double Reef Line

On yachts where the running rigging is led aft to the cockpit, you will want all the lines led aft to the cockpit. The worst setup is one where the halyard is led aft and the reef lines are left at the mast. Reefing a setup like this would require working the halyard in the cockpit, then run up to the mast to set the reef lines, then run back to the cockpit to tighten the halyard again. In a perfect world, this setup works just as described. In the real world, this setup leads to many trips between the mast and cockpit to carry out a reef. These problems could all be avoided by simply leaving all the lines at the mast or running all the lines back to the cockpit.

In the case of leading lines back to the cockpit, you have two choices with the reefing lines: Single or Double. 

Single or Double refers to how many reef lines are required to reef the sail properly. When reefing a sail, there are two places that need tension: the tack and the clew. With Double Reef Lines, the tack and clew are controlled by separate lines. With Single Reef Lines, the tack and clew are both controlled by a single line.

To properly decide which setup to go with, you need to weigh out the problems with each and find which system you feel more comfortable with. If you enjoy the benefits and don't mind the draw backs, then you have found your ideal setup!

Double Reef Line Setup

Double Reef Line Setup

Double Reef Line Setup Reefed

Double Reef Line Setup Reefed

Double Reef Line Setups allow you to tension the tack and clew from the cockpit, where you also have access to the main halyard when all the lines are led aft. The advantage of a double reef line setup is there is reduced friction, less resistance, and more control of tack and clew tension. 

The reduced friction directly leads to the reduced resistance in working the sail. Each turn a line makes adds friction to the system. If you want to shake a reef out of a sail, you will need to raise the sail by cranking in on the halyard. In a double reef line setup, the reef lines will twist and turn as they make their way from the cockpit to the mast, but then they will only have 2 major twists after that. A turning block on the boom will send the reef line up, and the cringle in the sail will send the reef line back down. Since the reef line only needs to work its way through one cringle, less line is needed to pass through the cringle to raise the sail and equates to less resistance.

Since the reef lines are separate, you are able to properly control the tension in the tack and clew independently. If you feel that the sail is a bit full, you can simply crank harder on the clew reef line to act as an outhaul and pull the sail flatter. 

While less resistance and more control over the sail does sound rather wonderful, double reef line setups do have their draw backs. For starters, you have an extra line to manage. If you are trying to reef in a hurry, you need to:

  1. Lower the main halyard
  2. Crank in on the reef tack line
  3. Crank in on the clew tack line
  4. Crank in on the main halyard

This might not sound that horrible, but most of the times, this is done with a single winch and a clutch bank. This means that you have to wind and unwind the winch drum in a hurry as you switch between lines. If you find that you need a bit more tension on a line, you will have to repeat these steps as you switch between them all.

The other problem with double reef lines is they are double the amount of lines led to the cockpit. If you have a single reef point, you will have 2 reef lines in the cockpit. If you have 3 reef points, you will have 6 reef lines in the cockpit! The cockpit spaghetti can quickly become overwhelming if you do not keep your lines organized and in a situation of panic, the spaghetti confusion can lead to the sail not getting reefed as quickly as it might be desired to have been reefed.

Single Reef Line Setup

Single Reef Line Setup

Single Reef Line Setup Reefed

Single Reef Line Setup Reefed

The alternative to double reef line setups is a single reef line setup. As you can imagine, it's most appealing feature is that it only requires one line to operate. This makes reefing a sail with multiple reef points less confusing. If you have 3 reef points, you will only have 3 reef lines leading to the cockpit! The lack of cockpit spaghetti will make this setup seem more enticing until you start to look at the problems that come with simplicity.

The procedure to reef is simple:

  1. Lower the main halyard
  2. Crank in on the reefing line
  3. Crank in on the main halyard

The first issue is the shared tension on the line. The tack and clew share the reef line, as it makes its journey from the boom to the clew cringle to the clew turning block to the tack turning block to the mast and then through all the twists and turns to get back to the cockpit. The setup can also be run in reverse where the fixed point is near the tack and the line returns to the mast from the end of the boom. Either way, the line runs a very long path with lots of turns resulting in a setup where the same line is supporting the loads of the clew and the tack.

If you feel that the sail is a bit full and you wish to flatten the sail out, you will need to tension the heck out of the line so that it can pull on the clew enough to produce the desired effect. The clew and the tack share the force. Any effort you put in to the reef line, only half the force reaches the clew as the tack is taking the other half.

Since the reef line is running to both points on the sail, the load on the reef line is also significantly increased. With a double reef line setup, your effort is only affecting one part of the sail. With a single reef line setup, any effort you do is going to affect the entire foot of the sail. 

All the twists and turns carried out by the sail will also greatly increase the amount of resistance involved in shaking out a reef. To raise the sail, the reef line will need to make its way through both cringles and that will add a lot of resistance and effort onto the arms of the person grinding the winch.

The last issue involved with single reef line setups is the length of line needed to rig the reefing system. Purchasing the length of line is no the big issues, the real problem is dealing with the line while you sail. Imagine a yacht with a really high reef point, say for a third reef, that is located 20 feet up the luff. The reef line will need to travel from the cockpit to the mast, up the mast, then up the sail to the cringle and back to the boom, and then again at the second cringle. This reef line is going to have to cross a 20 foot span four times!

Aside from all the length of line to get to the mast and to travel the boom, you will have 80 feet of line that needs to be worked to manage that sail. This means that when you go to shake out a reef, 80 feet of line will have to travel through the first cringle and 20 feet through the second cringle. When you go to reef, you will have to pull in 80 feet of line and then store it somewhere in the cockpit! While 80 feet may sound like a lot of line, but it gets worse. If that was the third reef, you will also need to haul in the reef line for the first and second reef line. If you don't the reef lines will lay slack and can fall into the water or get snagged on your deck. Not only will you have to deal with 80 feet for the 3rd reef, but the long length of line of the 1st and 2nd reef. This is how the cockpit spaghetti forms and gets really confusing when the lines are not properly color coded.

While it may sound like both of these systems are flawed in dumping all this line in the cockpit and adding a lot of extra resistance to the system, the truth is they do a great job of bringing the lines back to the cockpit. If you do not feel comfortable when you leave your cockpit, then this type of setup would be ideal for you as you would be able to raise, lower, and reef your mainsail all from the cockpit without setting foot on the deck.

Single and double reef line setups are a favorite among coastal cruisers and racers. Coastal cruisers love them because no one needs to leave the cockpit if the weather turns for the worse. Racers love them because it allows the crew to work the entire boat from a central location where they can easily hear commands. Blue water cruisers don't seem to favor either of these systems as the added resistance, effort, and spaghetti all lead to more points of failure and instead opt for the lines to be left at the mast where resistance is minimized as are failure points.

The final decision comes down to those who are sailing the yacht. All systems have their pros and cons, and finding a system that you enjoy the pros and don't mind the cons is the goal!