ADRA: ORC Rating

GPH

673.4

OSN

650.4

LOA

9.61 m

Displacement

3845 kg

Triple-Number Ratings

Lower is faster

Triple Inshore

Low

0.5914

Medium

0.8225

High

0.956

Triple Offshore

Low

0.7644

Medium

1.0128

High

1.1432

Boat Specifications

Dimensions

Length overall: 9.61 m
Beam: 3.21 m
Draft: 1.94 m
Displacement: 3845 kg
Crew weight: 480 kg
Wetted surface: 21.93 m²

Sails

Mainsail: 25.66 m²
Genoa: 26.56 m²
Spinnaker: 61.39 m²
Asymmetric spinnaker: 0 m²

Design

Type: FIRST 31.7
Builder: BENETEAU
Designer: FINOT
Year built: 1998
Stability index: 110.7

Performance data

Polar CSV

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

6,43.2,4.266302,52,4.78,60,5.06,75,5.26,90,5.17,110,5.17,120,5,135,4.5,146,3.968457,150,3.8
8,41.8,5.084,52,5.7,60,5.98,75,6.2,90,6.2,110,6.3,120,6.13,135,5.57,150,4.85,150.2,4.840018
10,40.6,5.702836,52,6.36,60,6.57,75,6.72,90,6.84,110,6.93,120,6.84,135,6.47,150,5.77,152,5.674176
12,39.4,6.082303,52,6.71,60,6.87,75,7.01,90,7.15,110,7.31,120,7.24,135,6.97,150,6.53,157,6.235709
14,38.7,6.227333,52,6.86,60,7.04,75,7.24,90,7.32,110,7.7,120,7.64,135,7.35,150,6.99,168.2,6.476873
16,38.2,6.260682,52,6.92,60,7.12,75,7.43,90,7.59,110,8.05,120,8.08,135,7.78,150,7.34,177.2,6.838164
20,38.8,6.274556,52,6.94,60,7.16,75,7.59,90,8.05,110,8.45,120,8.9,135,8.75,150,8.17,178.1,7.524137

Wind Speed	52°	60°	75°	90°	110°	120°	135°	150°
6	4.78	5.06	5.26	5.17	5.17	5	4.5	3.8
8	5.7	5.98	6.2	6.2	6.3	6.13	5.57	4.85
10	6.36	6.57	6.72	6.84	6.93	6.84	6.47	5.77
12	6.71	6.87	7.01	7.15	7.31	7.24	6.97	6.53
14	6.86	7.04	7.24	7.32	7.7	7.64	7.35	6.99
16	6.92	7.12	7.43	7.59	8.05	8.08	7.78	7.34
20	6.94	7.16	7.59	8.05	8.45	8.9	8.75	8.17

Wind Speed	Beat Angle	Beat VMG	Run Angle	Run VMG
6	43.2°	3.11	146°	3.29
8	41.8°	3.79	150.2°	4.2
10	40.6°	4.33	152°	5.01
12	39.4°	4.7	157°	5.74
14	38.7°	4.86	168.2°	6.34
16	38.2°	4.92	177.2°	6.83
20	38.8°	4.89	178.1°	7.52

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°	4.78	5.70	6.36	6.71	6.86	6.92	6.94
60°	5.06	5.98	6.57	6.87	7.04	7.12	7.16
75°	5.26	6.20	6.72	7.01	7.24	7.43	7.59
90°	5.17	6.20	6.84	7.15	7.32	7.59	8.05
110°	5.17	6.30	6.93	7.31	7.70	8.05	8.45
120°	5.00	6.13	6.84	7.24	7.64	8.08	8.90
135°	4.50	5.57	6.47	6.97	7.35	7.78	8.75
150°	3.80	4.85	5.77	6.53	6.99	7.34	8.17