Dufour 39 Wing keel

Sailboat specifications

The Dufour 39 is a 38’1” (11.6m) cruiser-racer sailboat designed by Frers Naval Architecture & Engineering (Argentina). She was built between 1982 and 1996 by Dufour (France) with 120 hulls completed. The Wing keel version is offered with a short keel fitted with large winglets. This configuration provides an interesting draft / low center of gravity / upwind performance trade-off.

The Dufour 39 is as well listed, on Boat-Specs.com, in Deep draft version (see all the versions compared).

Dufour 39's main features

Model: Dufour 39
Version: Wing keel
Hull type: Monohull
Category: Cruiser-racer sailboat
Sailboat builder: Dufour
Sailboat designer: Frers Naval Architecture & Engineering
Country: France
Construction: GRP (glass reinforced polyester):
- Hull: Single skin fiberglass polyester
- Deck: Sandwich fiberglass polyester
Number of hulls built: 120
First built hull: 1982
Last built hull: 1996
Appendages: Keel : wing keel
Helm: Single helm wheel
Rudder: Single spade rudder
Unsinkable: No
Trailerable: No
Former French navigation category: 1
Standard public price ex. VAT (indicative only): N/A €

Dufour 39's main dimensions

Overall length: 39’ 2”11.96 m
Hull length: 38’ 1”11.6 m
Waterline length: 30’ 6”9.3 m
Beam (width): 12’ 6”3.8 m
Draft: 5’ 7”1.7 m
Light displacement (M_LC): 14991 lb6800 kg
Ballast weight: 6989 lb3170 kg
Ballast type: Lead
French customs tonnage: 13.76 Tx

Dufour 39's rig and sails

Upwind sail area: 899 ft²83.5 m²
Downwind sail area: 1631 ft²151.5 m²
Mainsail area: 339 ft²31.5 m²
Genoa area: 560 ft²52 m²
Symmetric spinnaker area: 1292 ft²120 m²
I iFore triangle height (from mast foot to fore stay top attachment): 48’ 2”14.7 m
J iFore triangle base (from mast foot to bottom of forestay): 15’ 2”4.63 m
P iMainsail hoist measurement (from tack to head): 42’12.8 m
E iMainsail foot measurement (from tack to clew): 14’ 5”4.4 m
Rigging type: Sloop Marconi masthead
Mast configuration: Deck stepped mast
Rotating spars: No
Number of levels of spreaders: 2
Spreaders angle: 0 °
Spars construction: Aluminum spars

Dufour 39's performances

HN (French rating) iHN or "Handicap Nationale" is an empirical rating system used in France allowing various monohulls, of different sizes and designs, to race each other fairly. It is particularly suitable for cruiser and cruiser-racer. Therefore, by comparing these values, we can have an indication of the relative speed of 2 boats.: 22.0
Upwind sail area to displacement iThe ratio sail area to displacement is obtained by dividing the sail area by the boat's displaced volume to the power two-thirds. The ratio sail area to displacement can be used to compare the relative sail plan of different sailboats no matter what their size. Upwind: under 18 the ratio indicates a cruise oriented sailboat with limited performances especially in light wind, while over 25 it indicates a fast sailboat.: 250 ft²/T23.26 m²/T
Downwind sail area to displacement iThe ratio sail area to displacement is obtained by dividing the sail area by the boat's displaced volume to the power two-thirds. The ratio sail area to displacement can be used to compare the relative sail plan of different sailboats no matter what their size.: 454 ft²/T42.21 m²/T
Displacement-length ratio (DLR) iThe Displacement Length Ratio (DLR) is a figure that points out the boat's weight compared to its waterline length. The DLR is obtained by dividing the boat's displacement in tons by the cube of one one-hundredth of the waterline length (in feet). The DLR can be used to compare the relative mass of different sailboats no matter what their length: a DLR less than 180 is indicative of a really light sailboat (race boat made for planning), while a DLR greater than 300 is indicative of a heavy cruising sailboat.: 239
Ballast ratio iThe Ballast ratio is an indicator of stability; it is obtained by dividing the boat's displacement by the mass of the ballast. Since the stability depends also of the hull shapes and the position of the center of gravity, only the boats with similar ballast arrangements and hull shapes should be compared. The higher the ballast ratio is, the greater is the stability.: 47 %
Critical hull speed iAs a ship moves in the water, it creates standing waves that oppose its movement. This effect increases dramatically the resistance when the boat reaches a speed-length ratio (speed-length ratio is the ratio between the speed in knots and the square root of the waterline length in feet) of about 1.2 (corresponding to a Froude Number of 0.35) . This very sharp rise in resistance, between speed-length ratio of 1.2 to 1.5, is insurmountable for heavy sailboats and so becomes an apparent barrier. This leads to the concept of "hull speed". The hull speed is obtained by multiplying the square root of the waterline length (in feet) by 1.34.: 7.40 knots