First 235 Swing keel

Sailboat specifications

The First 235 is a 21’7” (6.57m) cruiser-racer sailboat designed by Finot Conq Architectes (France). She was built between 1986 and 1994 by Bénéteau (France) with 680 hulls completed. The Swing keel version features an appendage configuration without compromise between draft and performance. The only drawbacks are the space is taken inside and the effort needed to lift the keel....

The First 235 is as well listed, on Boat-Specs.com, in Fin keel version (see all the versions compared).

First 235's main features

Model: First 235
Version: Swing keel
Hull type: Monohull
Category: Cruiser-racer sailboat
Sailboat builder: Bénéteau
Sailboat designer: Finot Conq Architectes
Sailboat range: First
Country: France
Construction: GRP (glass reinforced polyester):
- Hull: Single skin fiberglass polyester
- Deck: Sandwich balsa fiberglass polyester
Number of hulls built: 680
First built hull: 1986
Last built hull: 1994
Appendages: Lifting keel : swing keel
Helm: Single tiller
Rudder: Single spade rudder
Unsinkable: No
Trailerable: Yes
Former French navigation category: 3
Standard public price ex. VAT (indicative only): N/A €

First 235's main dimensions

Overall length: 23’ 5”7.14 m
Hull length: 21’ 7”6.57 m
Waterline length: 20’ 11”6.36 m
Beam (width): 8’ 2”2.5 m
Waterline beam (width): 6’ 10”2.06 m
Draft: 5’ 8”1.75 m
Draft when appendages up: 2’ 2”0.66 m
Mast height from D_WL: 34’ 7”10.56 m
Fore freeboard: 3’ 1”0.94 m
Mid-ship freeboard: 2’ 8”0.82 m
Light displacement (M_LC): 3064 lb1390 kg
Maximum displacement (M_LDC): 4034 lb1830 kg
Ballast weight: 794 lb360 kg
Ballast type: Cast iron
French customs tonnage: 4.20 Tx

First 235's rig and sails

Upwind sail area: 346 ft²32.18 m²
Downwind sail area: 549 ft²50.99 m²
Mainsail area: 158 ft²14.69 m²
Genoa area: 188 ft²17.49 m²
Jib area: 82 ft²7.6 m²
Symmetric spinnaker area: 391 ft²36.3 m²
I iFore triangle height (from mast foot to fore stay top attachment): 27’ 10”8.46 m
J iFore triangle base (from mast foot to bottom of forestay): 7’ 11”2.4 m
P iMainsail hoist measurement (from tack to head): 26’ 7”8.1 m
E iMainsail foot measurement (from tack to clew): 10’ 4”3.15 m
Rigging type: Sloop Marconi 7/8
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

First 235'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.: 12.0
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.: 278 ft²/T25.84 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.: 441 ft²/T40.94 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.: 153
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.: 26 %
Wetted area: 128 ft²11.91 m²
Righting moment @ 1° iThe righting moment is a moment (torque) that tends to restore a boat to its previous position after heeling. Its value corresponds to the torque needed to heel the boat for this angle. Higher the righting moment is for an angle, greater is the stability.: 180 lb.ft25 kg.m
Maximum transverse section: 6 ft²0.56 m²
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.: 6.12 knots