Océanis 331 Keel and centerboard

Sailboat specifications

The Océanis 331 is a 32’10” (10m) cruising sailboat designed by Finot Conq Architectes (France). She was built between 1999 and 2005 by Bénéteau (France) with 822 hulls completed. The Keel and centerboard version features a centerboard inside of a short fin-keel allowing shoal draft while maintaining upwind capabilities.

The Océanis 331 is as well listed, on Boat-Specs.com, in Fin keel version (see all the versions compared).

Océanis 331's main features

Model: Océanis 331
Version: Keel and centerboard
Hull type: Monohull
Category: Cruising sailboat
Sailboat builder: Bénéteau
Sailboat designer: Finot Conq Architectes
Sailboat range: Océanis
Country: France
Construction: GRP (glass reinforced polyester):
- Hull: Single skin fiberglass polyester
- Deck: Sandwich balsa fiberglass polyester
Number of hulls built: 822
First built hull: 1999
Last built hull: 2005
Appendages: Centerboard : pivoting centerboard in the keel
Helm: Single helm wheel
Rudder: Single spade rudder
Unsinkable: No
Trailerable: No
EC design category iThe CE design category indicates the ability to cope with certain weather conditions (the sailboat is designed for these conditions) A: Wind < force 9, Waves < 10m B: Wind < force 8, Waves < 8m C: Wind < force 6, Waves < 4m D: Wind < force 4, Waves < 0,5m: A
Standard public price ex. VAT (indicative only): N/A €

Océanis 331's main dimensions

Overall length: 34’ 2”10.41 m
Hull length: 32’ 10”10 m
Waterline length: 30’ 6”9.3 m
Beam (width): 11’ 5”3.46 m
Draft: 6’ 11”2.1 m
Draft when appendages up: 3’0.9 m
Light displacement (M_LC): 11971 lb5430 kg
Ballast weight: 4255 lb1930 kg
Ballast type: Cast iron exterior ballast with steel centerboard
French customs tonnage: 11.90 Tx

Océanis 331's rig and sails

Upwind sail area: 606 ft²56.3 m²
Downwind sail area: 1124 ft²104.4 m²
Mainsail area: 273 ft²25.4 m²
Genoa area: 333 ft²30.9 m²
Symmetric spinnaker area: 850 ft²79 m²
I iFore triangle height (from mast foot to fore stay top attachment): 41’12.5 m
J iFore triangle base (from mast foot to bottom of forestay): 12’ 4”3.76 m
P iMainsail hoist measurement (from tack to head): 34’ 1”10.4 m
E iMainsail foot measurement (from tack to clew): 14’4.28 m
Rigging type: Sloop Marconi masthead
Mast configuration: Deck stepped mast
Rotating spars: No
Number of levels of spreaders: 1
Spreaders angle: Swept-back
Spars construction: Aluminum spars
Standing rigging: 1x19 strand wire continuous

Océanis 331's performances

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.: 196 ft²/T18.22 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.: 364 ft²/T33.79 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.: 191
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.: 36 %
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