Condition

Foot

Luff

Producer

Sails

Sail area

Mainsail

Mainsail guide: selection and specifications

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.

Original price was: € 1.150,00.Current price is: € 1.100,00.

Sail Area: 13.5m2
Luff: 8.05m
Foot: 2.9m
Leech: 8.45m

Original price was: € 745,00.Current price is: € 590,00.

Sail Area: 9m2
Luff: 6.3m
Foot: 2.35m
Leech: 6.65m

Original price was: € 6.665,00.Current price is: € 4.650,00.

Sail Area: 64.8m2
Luff: 18m
Foot: 6m
Leech: 18.75m

Original price was: € 6.665,00.Current price is: € 4.650,00.

Sail Area: 65.7m2
Luff: 18.2m
Foot: 6m
Leech: 18.9m

Original price was: € 6.665,00.Current price is: € 4.650,00.

Sail Area: 64.8m2
Luff: 18m
Foot: 6m
Leech: 18.75m

 1.975,00

Sail Area: 26m2
Luff: 11m
Foot: 3.85m
Leech: 11.47m

Original price was: € 6.665,00.Current price is: € 4.650,00.

Sail Area: 64.8m2
Luff: 18m
Foot: 6m
Leech: 18.75m

Original price was: € 6.665,00.Current price is: € 4.650,00.

Sail Area: 64.8m2
Luff: 18m
Foot: 6m
Leech: 18.75m

Original price was: € 6.665,00.Current price is: € 4.650,00.

Sail Area: 64.8m2
Luff: 18m
Foot: 6m
Leech: 18.75m

Original price was: € 5.800,00.Current price is: € 4.250,00.

Sail Area: 54m2
Luff: 16.4m
Foot: 5.9m
Leech: 17m

Original price was: € 4.900,00.Current price is: € 3.500,00.

Sail Area: 52m2
Luff: 15.8m
Foot: 5.4m
Leech: 16.7m

Original price was: € 5.125,00.Current price is: € 3.300,00.

Sail Area: 55m2
Luff: 16.53m
Foot: 5.75m
Leech: 17.25m

Definition and key measurements

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.

Mainsail categories

Full-batten mainsail

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

Partial-batten mainsail

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

In-mast furling mainsail

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

Storm trysail

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

Procurement and upcycling

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.