SCREWBALL — ORC Rating

GPH

694.2

OSN

676.3

LOA

8.292 m

Displacement

2219 kg

Triple-Number Ratings

Lower is faster

Triple Inshore

Low

0.6808

Medium

0.9021

High

1.0123

Triple Offshore

Low

0.8698

Medium

1.0877

High

1.1986

Boat Specifications

Dimensions

Length overall: 8.292 m
Beam: 2.8 m
Draft: 1.7 m
Displacement: 2219 kg
Crew weight: 394 kg
Wetted surface: 15.4 m²

Sails

Mainsail: 23.95 m²
Genoa: 21.22 m²
Spinnaker: 47.15 m²
Asymmetric spinnaker: 0 m²

Design

Type: Hunter Formula 28
Builder: Hunter Boats Ltd.
Designer: S. Jones
Year built: 1983

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.

6,40.8,4.385762,52,4.94,60,5.17,75,5.34,90,5.27,110,5.16,120,4.99,135,4.5,147.8,3.876184,150,3.79
8,40.3,5.179185,52,5.75,60,5.9,75,5.99,90,6.01,110,6.03,120,5.92,135,5.47,150,4.76,152.2,4.657572
10,38.3,5.54298,52,6.07,60,6.19,75,6.3,90,6.38,110,6.44,120,6.36,135,6.13,150,5.61,152.8,5.497987
12,37.2,5.649505,52,6.21,60,6.35,75,6.52,90,6.61,110,6.82,120,6.74,135,6.48,150,6.17,170.2,5.672778
14,37.2,5.724832,52,6.27,60,6.44,75,6.7,90,6.85,110,7.18,120,7.16,135,6.86,150,6.5,180,6.1
16,37.1,5.742342,52,6.3,60,6.49,75,6.82,90,7.08,110,7.44,120,7.54,135,7.27,150,6.86,180,6.43
20,37.5,5.785568,52,6.3,60,6.51,75,6.93,90,7.37,110,7.77,120,8.13,135,8.16,150,7.63,180,7.12

Wind Speed	52°	60°	75°	90°	110°	120°	135°	150°
6	4.94	5.17	5.34	5.27	5.16	4.99	4.5	3.79
8	5.75	5.9	5.99	6.01	6.03	5.92	5.47	4.76
10	6.07	6.19	6.3	6.38	6.44	6.36	6.13	5.61
12	6.21	6.35	6.52	6.61	6.82	6.74	6.48	6.17
14	6.27	6.44	6.7	6.85	7.18	7.16	6.86	6.5
16	6.3	6.49	6.82	7.08	7.44	7.54	7.27	6.86
20	6.3	6.51	6.93	7.37	7.77	8.13	8.16	7.63

Wind Speed	Beat Angle	Beat VMG	Run Angle	Run VMG
6	40.8°	3.32	147.8°	3.28
8	40.3°	3.95	152.2°	4.12
10	38.3°	4.35	152.8°	4.89
12	37.2°	4.5	170.2°	5.59
14	37.2°	4.56	180°	6.1
16	37.1°	4.58	180°	6.43
20	37.5°	4.59	180°	7.12

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