Bunt: The Gathered or Loose Section of a Sail When Reefed or Lowered
Definition:
The bunt is the loose, lower portion of a sail that hangs or gathers up when the sail is reefed, furled, or partly lowered. In normal sailing, it refers to the curved central part of the sail between the clews that fills with wind to provide power. When reefed, the bunt becomes the excess sailcloth that is tied up — often forming the so-called “sail centipede.”
Understanding the Bunt
In a well-set sail, the bunt is the area that holds the most wind and contributes most to driving the boat forward. When reefing, that same area of cloth becomes surplus to requirements and must be bundled and tied securely to prevent it from flogging in the wind or obstructing visibility.
The term is most often used when referring to mainsails or square sails, but it applies to any sail that can be reefed or stowed. A properly managed bunt ensures the sail remains tidy, balanced, and efficient whether fully set or reduced for heavy weather.
Applications in Sailing
Sail Shape:
The bunt’s curve or “belly” affects the sail’s performance. A fuller bunt increases power in light winds, while a flatter one gives better control in strong winds.
Reefing:
When the sail is reefed, the bunt becomes the folded or rolled-up section of sailcloth that needs to be tied and secured along the boom using the reefing points — creating the neat “sail centipede.”
Furling and Storage:
When a sail is dropped, the bunt is gathered and flaked to prevent creasing or chafing. Properly handling the bunt extends the sail’s life.
Examples of Usage
"After reefing, make sure the bunt is neatly tied and not hanging below the boom."
"The wind caught the bunt before we could tie in the reefing points, and it flapped wildly."
"In strong gusts, flattening the bunt of the mainsail helped steady the boat."
Visual Representation
Image Description:
Diagram of a mainsail showing the curved centre section (the bunt) when fully hoisted. A second illustration shows the same sail reefed, with the bunt gathered and tied along the boom using reefing points, forming a neat bundle of folded sailcloth.
Importance in Sailing
The bunt plays a key role in both sail aerodynamics and safety. Its shape determines how efficiently the sail harnesses wind power, and when reefed, how safely the sail can be reduced without damage. Managing the bunt correctly — whether shaping it for speed or securing it during a reef — keeps the boat balanced and the sail under control.
Related Terms
Sail Centipede:
The row of reefing ties that secure the bunt when reefed.
Reefing Points:
The reinforced eyelets used to tie up the bunt.
Cringle:
The larger reinforced holes at the sail’s corners for attaching reefing lines.
Draft (or Belly):
The depth or curve of the sail, particularly in the bunt area.
Foot:
The lower edge of a sail, from tack to clew.
Conclusion
The bunt may look like nothing more than spare cloth when the wind pipes up, but it’s vital to both performance and seamanship. Whether it’s catching the breeze in light airs or being tied neatly when reefed, a well-managed bunt keeps the sail efficient, tidy, and ready for whatever the weather brings.
