
Master your mainsail—learn to select the right materials, construction, and design, and trim it like a pro in any condition.
Your mainsail is one of the most essential—and expensive—components of your cruising rig. Offshore sailors must understand not only how to trim for performance, but how to select the right sail from the start. This course demystifies the decisions that go into mainsail design and teaches smart, practical trim techniques that will serve you for thousands of miles.



ONLINE COURSE OVERVIEW
This in-depth online course explores the critical components of mainsail design and performance for offshore cruisers. We’ll cover modern sail materials, construction methods, and key considerations when working with a sailmaker. You’ll also learn essential trimming strategies, how to optimize sail shape in a variety of wind conditions, and techniques for reefing and storm management. With the right sail and the right skills, your boat will be balanced, efficient, and a joy to handle offshore.
Who is this online class for?
This course is designed for intermediate-level sailors preparing for extended cruising or offshore passages. If you’ve got some experience under your belt and want to become more self-sufficient in choosing and trimming your mainsail, this class will help you level up.
What Will I Learn?
In this course, you’ll gain a solid foundation in mainsail trim, including the primary and secondary tools available and how to apply them effectively in various conditions. Learn reefing techniques, how and when to deploy a storm trysail, and how to work with a sailmaker to build the right sail for your rig. You’ll walk away with real-world knowledge for improving performance, safety, and longevity offshore.
List of Topics:
- Rig Designs
- Mainsail Designs
- Cruising Sail Materials
- Construction Details
- Light Air and Heavy Air Mainsail Use
- Reefing Techniques
- Mainsail Trim Basics
- Mainsail Trim Tools
- Mainsail Trim in Changing Conditions
MASTER YOUR MAINSAIL
Sail smarter, cruise farther
Your mainsail isn’t just a piece of gear, it’s the engine of your offshore cruising rig. The right sail, carefully chosen and expertly trimmed, can mean the difference between a balanced, efficient passagemaker and a boat that’s hard work in heavy weather. This course gives you the practical knowledge to select the right materials, construction, and design, and the trim skills to get the most out of it in any conditions.
Insight, Technique & Offshore Confidence
Led by expert sailmaker and seasoned cruiser Erica Georgaklis, this class demystifies the choices that go into building a great cruising mainsail and the techniques needed to trim it for safety, performance, and longevity. From understanding modern materials and construction details to mastering reefing, storm tactics, and fine-tuning sail shape, you’ll gain real-world strategies to keep your boat balanced and fast.
Real Experience from a Sailmaking Pro
Erica Georgaklis brings years of offshore experience and a deep sailmaking background to this class. Managing Port Townsend Sails and trained under renowned sailmaker Carol Hasse, she offers practical, hands-on knowledge for cruisers who want to make smart choices and sail with confidence. Whether you’re planning extended cruising or offshore passages, Mainsail Trim and Material Selection gives you the tools to make informed decisions and handle your boat like a pro.
YOUR HOSTs
Erica Georgaklis
Erica Georgaklis grew up sailing in New England and later settled in the Pacific Northwest, where she now manages Port Townsend Sails. With extensive cruising experience on both coasts, and offshore miles in Mexico and Scotland, Erica brings a rich background in sailmaking and seamanship. After working under legendary sailmaker Carol Hasse, Erica continues to share her deep knowledge of sail construction and trim with passionate cruisers around the world.
ONLINE CLASS REGISTRATION
@ 4:30 PM PT / 7:30 PM ET (90 min)
$39
$29
ON-DEMAND ACCESS
ASA MEMBER DISCOUNT
American Sailing Members can claim their discount in the Member Portal. If you're not a current member then for only $59/year you can join or renew today!