JPK 38 Fast Cruiser Swing keel

Sailboat specifications

The JPK 38 Fast Cruiser is a 37’4” (11.38m) fast cruising sailboat designed by Jacques Valer (France). She is built since 2012 by JPK (France). The Swing keel version adopts an appendage configuration without compromise between draft and performance. The only drawbacks are the space taken inside and the price of the system...

The JPK 38 Fast Cruiser is as well listed, on Boat-Specs.com, in Fin keel version (see all the versions compared).

JPK 38 Fast Cruiser's main features

Model: JPK 38 Fast Cruiser
Version: Swing keel
Hull type: Monohull
Category: Offshore fast cruising sailboat
Sailboat builder: JPK
Sailboat designer: Jacques Valer
Country: France
Construction: GRP (glass reinforced polyester):
Sandwich PVC fiberglass vinylester (vacuum infusion)
First built hull: 2012
Last built hull: Still in production
Appendages: Lifting keel : swing keel
Helm: Twin tillers
Rudder: Twin spade rudders
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): About
195 000 €
(2020)

JPK 38 Fast Cruiser's main dimensions

Hull length: 37’ 4”11.38 m
Waterline length: 34’ 1”10.4 m
Beam (width): 13’ 1”3.99 m
Draft: 8’ 11”2.7 m
Draft when appendages up: 4’ 4”1.3 m
Light displacement (M_LC): 11905 lb5400 kg
Ballast weight: 4189 lb1900 kg
Ballast type: Glass fiber/vinylester (infusion) fin with lead bulb

JPK 38 Fast Cruiser's rig and sails

Upwind sail area: 797 ft²74 m²
Downwind sail area: 1830 ft²170 m²
Mainsail area: 431 ft²40 m²
Genoa area: 366 ft²34 m²
Jib area: 269 ft²25 m²
Asymmetric spinnaker area: 1399 ft²130 m²
I iFore triangle height (from mast foot to fore stay top attachment): 49’ 8”15.15 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): 47’ 8”14.55 m
E iMainsail foot measurement (from tack to clew): 16’ 2”4.95 m
Rigging type: Sloop Marconi 9/10
Mast configuration: Deck stepped mast
Rotating spars: No
Number of levels of spreaders: 2
Spreaders angle: Swept-back
Spars construction: Aluminum spars (carbon fiber spars as an option)
Standing rigging: 1x19 strand wire

JPK 38 Fast Cruiser'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.: 259 ft²/T24.04 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.: 594 ft²/T55.23 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.: 136
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.: 35 %
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.: 7.83 knots