Dufour A9000 Deep draft

Sailboat specifications

The Dufour A9000 is a 38’11” (11.85m) cruiser-racer sailboat designed by Valentijn Design (Netherlands) and Michel Dufour (France). She was built between 1979 and 1983 by Dufour (France). The Deep draft version displays a deeper fin allowing a lower center of gravity and extra performance especially upwind.

Dufour A9000's main features

Model: Dufour A9000
Version: Deep draft
Hull type: Monohull
Category: Offshore cruiser-racer sailboat
Sailboat builder: Dufour
Sailboat designer: Valentijn Design & Michel Dufour
Country: France
Construction: Hull and deck: aluminum
First built hull: 1979
Last built hull: 1983
Appendages: Keel : fin without bulb
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 A9000's main dimensions

Overall length: 40’12.2 m
Hull length: 38’ 11”11.85 m
Waterline length: 31’ 6”9.6 m
Beam (width): 12’ 1”3.7 m
Draft: 6’ 8”2.05 m
Light displacement (M_LC): 19842 lb9000 kg
Ballast weight: 9259 lb4200 kg
Ballast type: Aluminum keel filled with lead

Dufour A9000's rig and sails

Upwind sail area: 1027 ft²95.4 m²
Downwind sail area: 1707 ft²158.6 m²
Mainsail area: 372 ft²34.6 m²
Genoa area: 654 ft²60.8 m²
Jib area: 422 ft²39.2 m²
Symmetric spinnaker area: 1335 ft²124 m²
I iFore triangle height (from mast foot to fore stay top attachment): 55’ 5”16.9 m
J iFore triangle base (from mast foot to bottom of forestay): 15’ 11”4.85 m
P iMainsail hoist measurement (from tack to head): 48’ 2”14.7 m
E iMainsail foot measurement (from tack to clew): 15’ 1”4.6 m
Rigging type: Sloop Marconi masthead
Mast configuration: Keel stepped mast
Rotating spars: No
Number of levels of spreaders: 2
Spreaders angle: 0 °
Spars construction: Aluminum spars
Standing rigging: 1x19 strand wire

Dufour A9000'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.: 237 ft²/T22.05 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.: 395 ft²/T36.66 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.: 288
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.: 7.52 knots