Mainsail types: battened vs in-mast furling explained
Sailing know-how · Mainsails
In this article, our Country Manager and former racer, Giannis Patsamanis, guides you through mainsail types. Therefore, you’ll learn how to choose and what to look for on charter.
In short
Charter yachts usually have one of two mainsail types. A battened mainsail keeps a good curve for better efficiency and pointing upwind, but takes more effort to hoist and reef. An in-mast furling mainsail rolls in or out quickly, even single-handed, but is flatter and can jam if furled badly. Choose battened if your crew likes hands-on sailing and a responsive boat; choose in-mast furling for easy, safe, minimal sail handling.
From the race course
Why your mainsail matters
Firstly, early in my sailing career, I spent most of my time racing in regattas. I had a good friend (not a sailor back then), who always called the traditional mainsail “the normal mainsail.”
It was just after I’d won my first Hellenic National Championship, and to my ear it sounded a bit off. I couldn’t convince him to say “battened main” or “slab-reefing main,” so the nickname stuck.
Since then, I’ve been lucky enough to race in many Hellenic National Grand Prix events. Along the way I won four national titles and a European Championship.
Racing taught me that sails are far more than just canvas in the wind. As a result, your mainsail choice changes how the boat feels, handles, and performs.
Also, that’s true across mainsail types, whether you’re chasing a trophy or enjoying a week’s cruise. When you book a yacht charter, you might not think twice about the mainsail, until you’re actually using it. For most of our guests, detailed racing jargon isn’t much help, so let’s keep it simple.
How a sail works
At its heart, the purpose of any sail is to generate lift – a bit like an aircraft wing. To do that efficiently, the sail needs to keep a stable, aerodynamic shape. So, that’s where battens come in.
In a battened mainsail, the sail is supported along its length and stored along the boom. In contrast, in-mast furling mainsails roll neatly into the mast, trading some shape stability for ease of handling.
The two types
Two common mainsail types on charter yachts
Now, let’s take a closer look.
1. Battened Mainsail
a.k.a. “normal mainsail”
- Shape & Performance: Battens keep a good curve for better efficiency and pointing upwind.
- Handling: More effort to hoist and reef, but a smoother, more balanced helm.
- Storage: Stows in a lazy bag along the boom. Zip it up or the sun and salt will eat it alive.
- Best for: Crews who like hands-on sailing and a responsive boat.
2. In-Mast Furling Mainsail
Rolls into the mast
- Shape & Performance: Flatter, with less trim control. Fine for cruising, less crisp upwind.
- Handling: Rolls in or out quickly, even single-handed. Perfect for families.
- Storage: Disappears inside the mast (no bag, no ties, no zip).
- Caution: Can jam if furled badly; keep the leech snug and choose the right wind angle when stowing.
- Best for: Crews who want easy, safe, minimal sail handling.
Which to choose
The takeaway
If you love the feel of a boat under sail and want maximum control, go for the battened main. And remember to zip that lazy bag.
(At 1.73 m / 5′8″, I get annoyed when I can’t reach it. The new diagonal zips make life easier though.)
If you want easier sail handling (some call it the lazy way), in-mast furling is unbeatable. Just respect its quirks.
Whichever mainsail you find on your charter, remember that it’s not about using the perfect mainsail. It’s about knowing how to make the most of what’s there. Each yacht’s mainsail type is listed in our flotilla fleets, so you can choose before you book, and our guide on how to choose a yacht for your sailing holiday covers what else to look for.
Plus, if you still prefer to call it “the normal mainsail”? Well, you’ll be in good company… that nickname has been sailing with me for years.
Common questions
Mainsail types: your questions answered
What is a battened mainsail?
A battened mainsail is supported along its length by battens and stored along the boom, usually in a lazy bag. The battens keep a good curve for better efficiency and pointing upwind.
What is an in-mast furling mainsail?
An in-mast furling mainsail rolls neatly into the mast, so it disappears inside it with no bag, ties, or zip. It rolls in or out quickly, even single-handed, trading some shape stability for ease of handling.
Which mainsail is best for families?
In-mast furling suits most families and crews who want easy, safe, minimal sail handling. A battened mainsail suits crews who like hands-on sailing and a responsive boat.
Can an in-mast furling mainsail jam?
Yes, it can jam if furled badly. Keep the leech snug and choose the right wind angle when stowing it.
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