A genoa is a large, overlapping jib sail on a sailboat that extends behind the mast, used to increase speed in light to moderate winds. Characterized by high surface area, it is often attached to a furler and trimmed via sheets leading to winch-mounted cars. Common sizes range from 110% to 155% of the foretriangle area.

Key Components of a Genoa Sail
Corners: Head (top), Tack (bottom forward, attached to deck), Clew (bottom aft, where sheets attach).

Edges: Luff (forward edge, attached to forestay/furler), Leech (after edge), Foot (bottom edge).

Performance Features: Telltales (thread indicators for trim), Leech Line (adjusts tension to prevent fluttering), and Anti-UV Cover (protects furled sail).

Genoa Control and Hardware
Genoa Tracks & Cars: Adjustable rails on the deck that control the sheet angle, determining sail shape and twist.

Sheets: Lines attached to the clew to control the sail's angle to the wind.

Roller Furling: A drum system allowing the sail to be rolled around the headstay to reduce size in high winds.

Sheet Leads: Fairleads/blocks on the track that manage the load and direction of the sheet.

The sail is typically sized based on the Percentage of the J-measurement (foretriangle), where a 150% genoa is "Genoa I" (largest) and 110% is "Genoa III" (smallest/working).