A mainsail is the primary driving sail set aft of the mast on the main boom or mast track. It accounts for 40–60 % of total sail power and determines balance, helm feel and heavy-weather behaviour. This page details the four core mainsail configurations—full-batten, partial-batten, in-mast furling and storm trysail—plus sizing, reefing and end-of-life options.
€ 245,00
€ 245,00
€ 245,00
€ 245,00
€ 245,00
€ 275,00
Original price was: € 475,00.€ 295,00Current price is: € 295,00.
€ 295,00
€ 295,00
€ 295,00
€ 295,00
€ 295,00
The mainsail fills the main triangle bounded by mast, boom and tack. Standard dimensions:
P = luff length (mast track from boom to black band)
E = foot length (boom from mast to black band)
Roach = extra curve beyond the straight line from head to clew
Area = (P × E) / 2 + roach allowance
Girths (MGUM, MGM, MGU) control shape when reefed.
Horizontal battens span clew to luff
Zero flutter, maximum projected area
Requires lazy-jacks or Dutchman for flake control
Ideal for performance cruisers and racers
Typical roach 12–18 %, supported by 5–7 full battens
3–4 short battens at upper leech only
Easier to hoist and flake by hand
Moderate roach (8–10 %)
Standard on boats under 30 ft or charter fleets
Vertical battens or none; zero roach
Rolls inside mast via continuous-line furler
Infinite reef points, single-line cockpit control
Trade-off: 15–20 % less drive than battened mainsail
Cloth: vertical-cut Dacron or hydra-net for roll stability
Separate sail, bright orange, 15–25 % of working mainsail area
Set on dedicated trysail track parallel to mast
Deep third reef replaces trysail on modern rigs
Required for World Sailing OSR Category 0/1
Send P/E measurements to info@resail.org for a matched second-hand mainsail or to arrange free collection of your retired sail. Every exchange keeps 20 m² of technical textile in circulation.
Sail Area: 17.5m2
Luff: 9.65m
Foot: 3.65m
Leech: 10.68m