Storm Trysail: Essential Heavy Weather Safety Sail

Bullet-proof, small, and bright orange, a storm trysail is designed to save a boat’s mainsail from winds over 45 knots. It flies behind the mast; it is a short, triangular sail with a “droopy clew” that is sheeted to the deck or boom. The ISAF states that the trysail shall not have a headboard or battens because those hard parts could severely injure someone while flogging in high winds. To keep the unsupported edges from fluttering, the leech and the foot are concave. The storm trysail must be made out of strong woven polyester, and it is recommended that the color be highly visible. This picture shows how well Storm Orange sails stand out in stormy conditions.

Trysails have a permanently attached pennant that allows the sail to be set above the gooseneck. The exact height of the trysail’s tack depends on where the sail will be sheeted – to the aft quarter or to the boom. The area of the storm trysail cannot be more than 0.175 PxE (luff measurement x foot measurement). If you ever plan to set a storm trysail, it is best to have a separate track on the mast for the sail. In a gale, it is difficult to remove the mainsail from the mast to bend on the storm trysail. Using a trysail protects your main that will be needed once the gale abates.

Design and Construction Features

Storm trysails are built with specific safety features and construction requirements that set them apart from standard sails:

Material: Constructed from strong woven polyester (Dacron) or HMPE fibers
Color: Manufactured in highly visible colors (typically bright orange, pink, or yellow) for safety
Shape: Triangular design with a distinctive “droopy clew” and concave leech and foot
Size: Limited to no more than 17.5% of the mainsail area (0.175 PxE)
Attachment: Features a permanent pennant for setting above the gooseneck
No Battens or Headboard: Designed without hard parts to prevent injury during high winds

How high the trysail is set depends on the proper sheeting angle.

Installation and Usage

Dedicated Track System

A separate track on the mast is strongly recommended for storm trysail installation. This setup offers several advantages:

Quick deployment in deteriorating conditions
No need to remove the mainsail in challenging weather
Reduced risk during sail changes
Improved safety for crew members

Sheeting Options

Storm trysails can be sheeted to either:

The aft quarter of the deck
The boom (with appropriate pennant height adjustment)

Tack Pennant should be marked so that the pennant can be tied off to the same spot every time the sail is used.

When to Use a Storm Trysail

Key situations for deploying your storm trysail include:

Wind speeds over 45 knots
Protecting your mainsail in severe conditions
When standard sail reduction (reefing) becomes insufficient
During sustained gale conditions

The “droopy clew” of the trysail allows the tack to be raised above the stack of mainsail luff cars when the sail is left on the boom.

When the trysail’s clew is attached to the boom, the main sheet can be used to trim the sail.

UK Sailmakers puts two slides at the head and tack of the storm trysail to spread the load at these highly loaded points. If the sail is inserted into a bolt rope track, we web on a 3-inch stainless steel slide at the head and tack.

Frequently Asked Questions

Why doesn’t a storm trysail have battens or a headboard?

Safety is the primary concern. In high winds, hard elements like battens or headboards can become dangerous projectiles and potentially injure crew members. The sail’s design compensates for these omissions with specific shape features.

How is the correct size determined?

Storm trysail size is calculated using the formula 0.175 PxE, where:

P = Mainsail luff length
E = Mainsail foot length
This ensures the sail is properly proportioned for your vessel’s specifications.

Why use a storm trysail instead of a deeply reefed mainsail?

A storm trysail offers several advantages:

Purpose-built for severe conditions
Protects your valuable mainsail from damage
Provides better sail shape in heavy weather
Can be set on a separate track for safer deployment
Designed specifically for extreme wind conditions

Maintenance and Care

To ensure your storm trysail is ready when needed:

Regular inspections of sail material and stitching
Check pennant and attachment points annually
Practice installation in moderate conditions
Store in an easily accessible location
Keep track and hardware well-maintained
Document and repair any damage promptly

Racing Requirements and Regulations

For racing vessels, storm trysails must comply with World Sailing’s Offshore Special Regulations, which specify:

Material requirements
Size limitations
Visibility standards
Construction specifications
Attachment methods

Investment Considerations

When purchasing a storm trysail, consider:

Boat size and type
Expected sailing conditions
Racing requirements if applicable
Quality of construction
Ease of handling
Track installation options

A storm trysail represents a crucial safety investment for any sailing vessel. While it may see limited use, its importance cannot be overstated when conditions deteriorate. Proper sizing, installation, and familiarity with its use can make the difference between safely managing severe weather and risking damage to your vessel or standard sailing inventory.

Remember, the time to practice using your storm trysail is in moderate conditions, not when you actually need it. Regular drills and proper maintenance ensure this essential safety equipment will perform as intended when challenging conditions arise.