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Lazy Jacks

| Sail & Rigging | May 2, 2015

Installation; Mainsail handling systems

The following articles describe the various systems available to handle sails without having to or reduce the amount of manual labor required to handle them.

These systems make it easy to raise lower and reef the sail . First up are Lazy Jacks which are the cheapest and easiest method of handling a mainsail.

Lazy Jacks

vendee roxy

The Lazy Jacks sail system is a method of containing the main sail when its lowered or during reefing. Lazy jacks are the simplest and cheapest mainsail handling system available. The Lazy Jack lines are installed either side of the mainsail; attached high up in the mast and down to either side of the boom. Since the jacks are either side of the mainsail it can be dropped and is captured between the lines.

Lazy Jacks will not flake the sail neatly as the Dutchman system does but it will hold the sail on the boom.

The picture shows Roxy finishing the Vendee Globe race and you can see the lazy jacks attached to a white cover along the length of the boom. These Sailors choose Lazy jack systems over Dutchman due to the extreme conditions they sail in. If the mainsail gets blown around the vertical lazy jacks capture the sail.

Lazy Jacks V Dutchman

Harken single leg system and double leg inset


The difference between Lazy Jacks and the Dutchman system is the lines of a Lazy Jack system are positioned either side of the mainsail, while the Dutchman line goes through the sail. The mainsail is stowed between the Lazy Jacks.

The Lazy Jacks lines capture or cradle the mainsail as it drops. Lazy Jacks will work with a mainsail with a bolt rope, while the Dutchman system needs slides.

The Lazy Jack system is much cheaper than a Dutchman system and no modification of the sail is required (although full battens work better),

The lazy jacks are attached to the mast with pop rivets or screws and the same at the bottom end . This process is relatively cheap and fast although you will need to go aloft.

With a Dutchman system when you are reefing or dropping the mainsail in heavy wind conditions the Dutchman filament lines drag on the discs and that may prevent the sail dropping easily. This is why the Vendee round the world racers use Lazy jacks.

lazy Jacks Layout (number of legs)


The lazy jacks start with one line mounted high up on the mast. This one line then splits in to two more lines and its possible to make as many legs as you need.


The simplest system has just one top leg and splits into two bottom legs. You can ad more bottom legs as required for larger mainsails.





The 60 foot long Vendee Globe boats like Roxy and PRB have 3 legs which split into 7 legs for the very long boom they have. You can add as many legs as you like, but I would follow the boat manufacturers recommendation.


Lazy Jacks installation tips

The best results with Lazy Jacks is by using full length battens. Short or regular batters end up getting caught in the Lazy jack lines. With full length battens the mainsail folds down in a stiff manner in between the lines and does not flop around.

When you hoist the mainsail and its fully raised the lazy jack lines should have some slack in them. The slack  allows the mainsail to set properly.

harken lazy jacks

The Harken Diagram, shows the lazy Jack legs being held outboard at the spreaders, which helps separate the sail, from the Lazy Jack Legs.

The boom cover will need to be modified unless you pull the Lazy Jack line lined forward after the sail has been dropped and secured. The modification includes slits and zippers or Velcro where the Lazy Jack Lines attach to the boom.

Lots of sailboat classes have descriptions on the Class forums about how to install Lazy Jacks or Dutchman systems.Lazy jacks and Mainsail cover

PRB Vendee globe racer


If you combine the Lazy Jack system with a mainsail luff track and slide system, the front of the sail may flake itself somewhat, and then you can tidy up later.

In the case of the vendee Globe boats the lazy jacks are attached not directly to the boom but to canvas which is in turn attached to the boom. This picture of PRB, shows how the canvas captures the huge mainsail on these boats. Stack packs are versions of this concept.


Lazy Jack Manufacturers

It is quite feasible for you to make your own Lazy Jack system, many do. However buying a pre made kit takes some of the time out of the project.

Harken and Schaefer are two of the manufacturers for lazy Jacks. The Schaefer system is a bit more expensive, but has a feature allowing the lazy Jacks to be pulled forward which removes the need for boom cover modification.

Each have sizes based on boats length from 21ft to 48 ft. Both are available through the links below.

Most of marine stores have ready to go Lazy jack systems. All you need to do is install the legs, all the lines blocks and cleats are provided.

The Ezjacks system lets you pull the lazy jack lines forward. This enables you to use your existing mainsail cover. Otherwise you will need to modify you main cover with slits where the lower legs meet the boom.


Other Sail handling systems

    • Mainsail Furling and Reefing systems
    • Lazy jacks
    • Dutchman system
    • Roller furling systems (headsails)


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