UNDERWOOD — ORC Rating

GPH

785.6

OSN

757

LOA

9.32 m

Displacement

5098 kg

Triple-Number Ratings

Lower is faster

Triple Inshore

Low

0.5033

Medium

0.7017

High

0.8405

Triple Offshore

Low

0.6498

Medium

0.8697

High

0.9964

Boat Specifications

Dimensions

Length overall: 9.32 m
Beam: 3.29 m
Draft: 1.82 m
Displacement: 5098 kg
Crew weight: 350 kg
Wetted surface: 21.15 m²

Sails

Mainsail: 18.55 m²
Genoa: 19.18 m²
Spinnaker: 57.4 m²
Asymmetric spinnaker: 0 m²

Design

Type: DUFOUR 31
Builder: TAYLOR
Designer: M. DUFOUR
Year built: 1975
Stability index: 122.6

Velocity Prediction

Polar CSV

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

6,44.4,3.457095,52,3.82,60,4.05,75,4.2,90,4.5,110,4.59,120,4.45,135,4.03,147.5,3.557067,150,3.47
8,42.9,4.17723,52,4.64,60,4.87,75,5.04,90,5.43,110,5.56,120,5.42,135,5.01,150,4.44,151.4,4.385051
10,41.8,4.654744,52,5.21,60,5.45,75,5.65,90,6.03,110,6.14,120,6.07,135,5.77,150,5.24,155,5.042437
12,41.4,5.052585,52,5.63,60,5.84,75,6.03,90,6.33,110,6.46,120,6.42,135,6.23,150,5.87,161,5.489051
14,40.6,5.347232,52,5.92,60,6.09,75,6.26,90,6.51,110,6.7,120,6.68,135,6.53,150,6.27,173.6,5.786059
16,40,5.534927,52,6.1,60,6.26,75,6.43,90,6.6,110,6.9,120,6.91,135,6.78,150,6.54,178.4,6.162403
20,39.9,5.683261,52,6.25,60,6.44,75,6.66,90,6.75,110,7.24,120,7.39,135,7.29,150,7,179,6.671016

Wind Speed	52°	60°	75°	90°	110°	120°	135°	150°
6	3.82	4.05	4.2	4.5	4.59	4.45	4.03	3.47
8	4.64	4.87	5.04	5.43	5.56	5.42	5.01	4.44
10	5.21	5.45	5.65	6.03	6.14	6.07	5.77	5.24
12	5.63	5.84	6.03	6.33	6.46	6.42	6.23	5.87
14	5.92	6.09	6.26	6.51	6.7	6.68	6.53	6.27
16	6.1	6.26	6.43	6.6	6.9	6.91	6.78	6.54
20	6.25	6.44	6.66	6.75	7.24	7.39	7.29	7

Wind Speed	Beat Angle	Beat VMG	Run Angle	Run VMG
6	44.4°	2.47	147.5°	3
8	42.9°	3.06	151.4°	3.85
10	41.8°	3.47	155°	4.57
12	41.4°	3.79	161°	5.19
14	40.6°	4.06	173.6°	5.75
16	40°	4.24	178.4°	6.16
20	39.9°	4.36	179°	6.67

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