An in‑boom furling system is a mainsail‑handling setup where the sail furls horizontally around the mandrel, inside the boom, rather than vertical inside the mast.

‍How it works: A rotating mandrel inside the boom. When you activate the furling mechanism - with our electric or manual solution - the mandrel turns and furls the mainsail neatly into the boom.  

‍Why choose in-boom furling: The system allows for the use of a fully battened mainsail, delivering superior sail shape and performance, compared with most alternative furling systems. Reefing can be carried out safely and easily from the cockpit, while the sail remains well-protected inside the boom.

For more information, go to Product.

Sailors often experience complications with the furling line during hoisting. The MAINFURL MLS system eliminates these issues by allowing the mandrel to rotate freely when the coupling element is disengaged - preventing line drive jamming.

Safety becomes critical as wind loads increase. The MAINFURL MLS system incorporates an advanced locking mechanism that securely prevents the mainsail from unfurling when the coupling mechanism is engaged, taking the load off the furling line - this is absolutely essential feature for maintaining full control of the mainsail in demanding conditions.

For more information, go to MLS.

The MAINFURL MLS system enhances safety during both reefing and hoisting through its locking mechanism – allowing the mandrel to rotate freely when hoisting, to avoid jamming of the furling line, as well as locking the mandrel when reefed. Essentially, the sail will not move unless you want it to, ensuring a safer time on the water, no matter the conditions.

Safety becomes critical as wind loads increase. The MAINFURL MLS system incorporates an advanced locking mechanism that securely prevents the mainsail from unfurling when the coupling mechanism is engaged, taking the load off the furling line - this is absolutely essential feature for maintaining full control of the mainsail in demanding conditions.

For more info, go to MLS.

Yes. The MAINFURL in-boom furling system is retrofit-friendly, for all yachts from 35' to 60'.  

The MAINFURL MLS system is likewise fully retrofit-compatible and can easily be integrated into existing MAINFURL in-boom furling installations, making it an ideal upgrade for yachts, already equipped with a MAINFURL in-boom furling system.

For a closer look at our system, go to Product.

Yes, in some cases this may be possible. Please contact us to discuss compatibility with your existing furling system.

Find the contact form under - Contact.

With the MAINFURL MLS System, furling line jamming is not possible.

For more information on the MLS, go to MLS.

The MAINFURL MLS system enhances safety by reducing the physical workload and minimizing deck exposure for a small crew. Its locking mechanism prevents the mainsail from unfurling - especially important when reefed in increasing winds - providing safer sail control in challenging conditions.  

Additionally, the system allows the mainsail to be hoisted without friction or line drag, thanks to a freely rotating mandrel in the release state. This simplifies handling and avoids common furling‑line complications, making sail operations more predictable and safer.  The result is safer, easier, and more confident sail handling in all conditions.

For more information, go to MLS.

Operating the mainsail with the MAINFURL MLS System is simple and only requires a small number of steps, all to ensure effortless mainsail operation.  

Hoisting the mainsail by:  
1. Pull the MLS line to unlock the system.  
2. Position the boom in the right angle.  
3. Ease the mainsheet off.  4. Hoist the mainsail.    

Furling the mainsail by:  
1. Release the MLS line to lock the system.  
2. Position the boom in the right angle.  
3. Attach the endless furling line to a winch.  
4. Ease the mainsheet off.  
5. Take the main halyard (place it around a winch by one turn, to create some resistance) in one hand and push the winch-button with the other to furl the mainsail.

For more information, go to Manuals.

With normal and regular use, the MAINFURL in-boom furling system will last as long as your boat, or as long as you need it.  

The quality of our products is the pride of MAINFURL, and our team strives to ensure the best products and the best service.  

For more information on the MAINFURL in-boom furling system, go to Product.

Yes, however, our system demands an electric winch. But it is always possible to furl manually.
 
The MLS system itself is manually controlled, but reliant on an electric winch. If you have one of MAINFURL’s electronic solutions, the emergency drive must be activated, before you can furl manually. In the unlikely event of a total loss of power, we recommend that you either furl it manually or that you put the mainsail on deck.  

For more information, go to Manuals.

The MAINFURL in-boom furling system is a one-off product, designed to the specific yacht. For a more details, please don't hesitate to contact us or our dealers - all information can be found under Contact.

Both systems are of the highest possible quality, with the difference between our manual MLS-system and our electronic option being that the MLS uses a furling line to turn the mandrel, while the electronic option has an in-built Reckmann motor, in the mandrel.  

The MLS option functions through a furling line attached to an electronic powered winch, while the electronic option is operated through an in-cockpit push-button system.

For more information, go to Product.

The electronic option consists of a Reckmann motor, built into the mandrel – this is made as an exact fit. This is attached to the boats electronic system, while being used through push-buttons, in the cockpit.  

There are several options to extend the system, for example a vang that can be configured to the exact furling angle, by the push of a button inside the cockpit.

For more information, go to Product.

This varies; however, our electronic option fits all boats. We recommend the electronic option for boats from 60’ and up.

For any further questions, feel free to Contact us.

The MAINFURL in‑boom furling system does not require any extra maintenance; a good rinse is sufficient. However, according to good seamanship, lines and spectra loops should be checked frequently for wear and tear.

MAINFURL places a strong emphasis on good service and availability. We always provide support via telephone or e‑mail. If needed, we are fully prepared to find a solution either on site or at our workshop in Denmark.

For any enquiries, please don't hesitate to contact us - Contact.