Sealord 39 Ketch

Sailboat specifications

The Sealord 39 is a 38’6” (11.73m) cruising sailboat designed by Dubois Naval Architects (United Kingdom). She was built between 1983 and 1987 by Westerly (United Kingdom) with 42 hulls completed. The Ketch version displays a divided sail plan guarantying less effort and better balance adjustment.

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

Sealord 39's main features

Model: Sealord 39
Version: Ketch
Hull type: Monohull
Category: Offshore cruising sailboat
Sailboat builder: Westerly
Sailboat designer: Dubois Naval Architects
Country: United Kingdom
Construction: Hull and deck: GRP (glass reinforced polyester)
Number of hulls built: 42
First built hull: 1983
Last built hull: 1987
Appendages: Keel : fin without bulb
Helm: Single helm wheel
Rudder: Single spade rudder
Unsinkable: No
Trailerable: No
Standard public price ex. VAT (indicative only): N/A €

Sealord 39's main dimensions

Hull length: 38’ 6”11.73 m
Waterline length: 32’ 6”9.9 m
Beam (width): 13’ 2”4.01 m
Draft: 5’ 6”1.68 m
Mast height from D_WL: 48’ 4”14.72 m
Light displacement (M_LC): 18501 lb8392 kg
Ballast weight: 8001 lb3629 kg

Sealord 39's rig and sails

Upwind sail area: 974 ft²90.48 m²
Downwind sail area: 1793 ft²166.56 m²
Mainsail area: 274 ft²25.45 m²
Mizzen sail area: 108 ft²10.03 m²
Genoa area: 592 ft²55 m²
Solent area: 325 ft²30.19 m²
Jib area: 217 ft²20.16 m²
Stormjib area: 125 ft²11.6 m²
Symmetric spinnaker area: 1411 ft²131.08 m²
Gennaker area: 1019 ft²94.67 m²
Rigging type: Ketch Marconi masthead
Mast configuration: Deck stepped mast
Rotating spars: No
Number of levels of spreaders: 1
Spreaders angle: 0 °
Spars construction: Aluminum spars
Standing rigging: 1x19 strand wire continuous

Sealord 39'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.: 236 ft²/T21.91 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.: 434 ft²/T40.33 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.: 245
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.: 43 %
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.: 7.64 knots