Sun Way 21 Keel and centerboard

Sailboat specifications

The Sun Way 21 is a 20’8” (6.3m) cruising sailboat designed by J&J Design (Slovenia). She was built between 1989 and 1994 by Jeanneau (France) with 532 hulls completed. The Keel and centerboard version features a centerboard inside of a short fin-keel allowing shoal draft while maintaining upwind capabilities.

The Sun Way 21 is as well listed, on Boat-Specs.com, in Wing keel version (see all the versions compared).

Sun Way 21's main features

Model: Sun Way 21
Version: Keel and centerboard
Hull type: Monohull
Category: Coastal cruising sailboat
Sailboat builder: Jeanneau
Sailboat designer: J&J Design
Country: France
Construction: GRP (glass reinforced polyester):
- Hull: Single skin fiberglass polyester
- Deck: Sandwich balsa fiberglass polyester
Number of hulls built: 532
First built hull: 1989
Last built hull: 1994
Appendages: Centerboard : pivoting centerboard in the keel
Helm: Single tiller
Rudder: Single spade rudder
Unsinkable: Yes
Trailerable: Yes
Former French navigation category: 3
Standard public price ex. VAT (indicative only): N/A €

Sun Way 21's main dimensions

Overall length: 21’ 4”6.5 m
Hull length: 20’ 8”6.3 m
Waterline length: 17’ 11”5.45 m
Beam (width): 8’ 2”2.49 m
Draft: 2’ 1”0.65 m
Draft when appendages up: 4’ 4”1.3 m
Light displacement (M_LC): 1852 lb840 kg
Ballast weight: 441 lb200 kg
Ballast type: Cast iron exterior ballast with steel centerboard
French customs tonnage: 2.97 Tx

Sun Way 21's rig and sails

Upwind sail area: 248 ft²23 m²
Downwind sail area: 398 ft²37 m²
Mainsail area: 129 ft²12 m²
Genoa area: 118 ft²11 m²
Symmetric spinnaker area: 269 ft²25 m²
I iFore triangle height (from mast foot to fore stay top attachment): 23’7 m
J iFore triangle base (from mast foot to bottom of forestay): 7’ 5”2.25 m
P iMainsail hoist measurement (from tack to head): 24’ 11”7.6 m
E iMainsail foot measurement (from tack to clew): 8’ 11”2.7 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

Sun Way 21'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.: 9.0
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/T25.83 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.: 447 ft²/T41.56 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.: 147
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.: 24 %
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.: 5.67 knots