J-Rover: ORC Rating

GPH

595.7

OSN

578.9

LOA

12.009 m

Displacement

5663 kg

Triple-Number Ratings

Lower is faster

Triple Inshore

Low

0.6914

Medium

0.9278

High

1.0599

Triple Offshore

Low

0.8879

Medium

1.1336

High

1.2621

Boat Specifications

Dimensions

Length overall: 12.009 m
Beam: 3.77 m
Draft: 2.17 m
Displacement: 5663 kg
Crew weight: 525 kg
Wetted surface: 28.62 m²

Sails

Mainsail: 41.2 m²
Genoa: 39.09 m²
Spinnaker: 114.86 m²
Asymmetric spinnaker: 0 m²

Design

Type: J-39
Builder: J-Boats
Designer: R.Johnstone
Year built: 1991

Performance data

Polar CSV

Each row is TWS followed by TWA and boat-speed pairs. Paste it directly into Offwind or compatible navigation software.

6,42,4.951928,52,5.57,60,5.86,75,6.09,90,6.02,110,5.93,120,5.79,135,5.24,142.5,4.840214,150,4.44
8,40.9,5.887385,52,6.61,60,6.86,75,7.03,90,7,110,7.11,120,7,135,6.48,148,5.68364,150,5.57
10,39.8,6.494998,52,7.16,60,7.33,75,7.47,90,7.48,110,7.67,120,7.62,135,7.32,150,6.58,150.5,6.549047
12,38.2,6.655156,52,7.37,60,7.55,75,7.74,90,7.8,110,8.06,120,8.08,135,7.79,150,7.32,156.5,7.011536
14,37.7,6.736402,52,7.45,60,7.65,75,7.96,90,8.1,110,8.33,120,8.54,135,8.28,150,7.76,174,7.068723
16,37.5,6.793946,52,7.5,60,7.72,75,8.1,90,8.37,110,8.57,120,8.9,135,8.79,150,8.21,180,7.54
20,37.5,6.945203,52,7.63,60,7.84,75,8.24,90,8.76,110,8.96,120,9.43,135,9.96,150,9.21,180,8.39

Wind Speed	52°	60°	75°	90°	110°	120°	135°	150°
6	5.57	5.86	6.09	6.02	5.93	5.79	5.24	4.44
8	6.61	6.86	7.03	7	7.11	7	6.48	5.57
10	7.16	7.33	7.47	7.48	7.67	7.62	7.32	6.58
12	7.37	7.55	7.74	7.8	8.06	8.08	7.79	7.32
14	7.45	7.65	7.96	8.1	8.33	8.54	8.28	7.76
16	7.5	7.72	8.1	8.37	8.57	8.9	8.79	8.21
20	7.63	7.84	8.24	8.76	8.96	9.43	9.96	9.21

Wind Speed	Beat Angle	Beat VMG	Run Angle	Run VMG
6	42°	3.68	142.5°	3.84
8	40.9°	4.45	148°	4.82
10	39.8°	4.99	150.5°	5.7
12	38.2°	5.23	156.5°	6.43
14	37.7°	5.33	174°	7.03
16	37.5°	5.39	180°	7.54
20	37.5°	5.51	180°	8.39

VPP POLAR · BOAT SPEED BY TWAKT

TRUE WIND ANGLE —

READ AT ANGLE

Hover or tap the chart, or use the slider, to read boat speeds.

True wind speed 6 kt8 kt10 kt12 kt14 kt16 kt20 kt

Data table

Boat speed by true wind angle and true wind speed
TWA	Boat speed in 6 kt (kt)	Boat speed in 8 kt (kt)	Boat speed in 10 kt (kt)	Boat speed in 12 kt (kt)	Boat speed in 14 kt (kt)	Boat speed in 16 kt (kt)	Boat speed in 20 kt (kt)
0°	0.00	0.00	0.00	0.00	0.00	0.00	0.00
52°	5.57	6.61	7.16	7.37	7.45	7.50	7.63
60°	5.86	6.86	7.33	7.55	7.65	7.72	7.84
75°	6.09	7.03	7.47	7.74	7.96	8.10	8.24
90°	6.02	7.00	7.48	7.80	8.10	8.37	8.76
110°	5.93	7.11	7.67	8.06	8.33	8.57	8.96
120°	5.79	7.00	7.62	8.08	8.54	8.90	9.43
135°	5.24	6.48	7.32	7.79	8.28	8.79	9.96
150°	4.44	5.57	6.58	7.32	7.76	8.21	9.21