ERA ORA: ORC Rating

GPH

691.9

OSN

674.4

LOA

9.35 m

Displacement

4891 kg

Triple-Number Ratings

Lower is faster

Triple Inshore

Low

0.5609

Medium

0.7771

High

0.9394

Triple Offshore

Low

0.7425

Medium

0.9827

High

1.1355

Boat Specifications

Dimensions

Length overall: 9.35 m
Beam: 3.31 m
Draft: 1.9 m
Displacement: 4891 kg
Crew weight: 500 kg
Wetted surface: 24.09 m²

Sails

Mainsail: 30.03 m²
Genoa: 25.29 m²
Spinnaker: 0 m²
Asymmetric spinnaker: 0 m²

Design

Type: Dufour 310 GL
Builder: Dufour
Designer: Felci
Year built: 2004

Performance data

Polar CSV

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

6,45,4.143646,52,4.59,60,5.03,75,5.48,90,5.58,110,5.24,120,4.85,135,4.3,145,3.84544,150,3.64
8,42.9,4.873435,52,5.53,60,5.98,75,6.42,90,6.52,110,6.24,120,5.87,135,5.34,147,4.769453,150,4.62
10,42,5.463269,52,6.27,60,6.62,75,6.89,90,6.99,110,6.81,120,6.65,135,6.21,147.5,5.572739,150,5.43
12,41.6,6.004295,52,6.68,60,6.93,75,7.18,90,7.29,110,7.15,120,7.06,135,6.79,147.8,6.275163,150,6.13
14,39.8,6.273726,52,6.87,60,7.12,75,7.42,90,7.59,110,7.47,120,7.38,135,7.13,150,6.63,172.5,5.900479
16,39,6.433798,52,7.02,60,7.23,75,7.64,90,7.9,110,7.83,120,7.73,135,7.43,150,6.95,175,6.444523
20,39,6.523871,52,7.15,60,7.39,75,7.89,90,8.45,110,8.61,120,8.51,135,8.12,150,7.44,178,7.104328

Wind Speed	52°	60°	75°	90°	110°	120°	135°	150°
6	4.59	5.03	5.48	5.58	5.24	4.85	4.3	3.64
8	5.53	5.98	6.42	6.52	6.24	5.87	5.34	4.62
10	6.27	6.62	6.89	6.99	6.81	6.65	6.21	5.43
12	6.68	6.93	7.18	7.29	7.15	7.06	6.79	6.13
14	6.87	7.12	7.42	7.59	7.47	7.38	7.13	6.63
16	7.02	7.23	7.64	7.9	7.83	7.73	7.43	6.95
20	7.15	7.39	7.89	8.45	8.61	8.51	8.12	7.44

Wind Speed	Beat Angle	Beat VMG	Run Angle	Run VMG
6	45°	2.93	145°	3.15
8	42.9°	3.57	147°	4
10	42°	4.06	147.5°	4.7
12	41.6°	4.49	147.8°	5.31
14	39.8°	4.82	172.5°	5.85
16	39°	5	175°	6.42
20	39°	5.07	178°	7.1

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°	4.59	5.53	6.27	6.68	6.87	7.02	7.15
60°	5.03	5.98	6.62	6.93	7.12	7.23	7.39
75°	5.48	6.42	6.89	7.18	7.42	7.64	7.89
90°	5.58	6.52	6.99	7.29	7.59	7.90	8.45
110°	5.24	6.24	6.81	7.15	7.47	7.83	8.61
120°	4.85	5.87	6.65	7.06	7.38	7.73	8.51
135°	4.30	5.34	6.21	6.79	7.13	7.43	8.12
150°	3.64	4.62	5.43	6.13	6.63	6.95	7.44