Back Bay — ORC Rating

GPH

631.8

OSN

612.7

LOA

11.906 m

Displacement

8462 kg

Triple-Number Ratings

Lower is faster

Triple Inshore

Low

0.6522

Medium

0.8774

High

1.0049

Triple Offshore

Low

0.8342

Medium

1.0705

High

1.1873

Boat Specifications

Dimensions

Length overall: 11.906 m
Beam: 3.65 m
Draft: 2.06 m
Displacement: 8462 kg
Crew weight: 750 kg
Wetted surface: 33.44 m²

Sails

Mainsail: 37.17 m²
Genoa: 57.18 m²
Spinnaker: 124.34 m²
Asymmetric spinnaker: 124.75 m²

Design

Type: CAL 39-2 TM (1-147
Builder: JENSEN
Designer: LAPWORTH
Year built: 1978
Stability index: 123.3

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.

6,43,4.785646,52,5.31,60,5.57,75,5.72,90,5.59,110,5.54,120,5.38,135,4.88,145.1,4.365045,150,4.14
8,41.2,5.595317,52,6.22,60,6.44,75,6.57,90,6.5,110,6.63,120,6.5,135,6.01,149.8,5.264529,150,5.25
10,39.6,6.09983,52,6.76,60,6.93,75,7.05,90,7.08,110,7.24,120,7.17,135,6.85,150,6.18,152.3,6.065099
12,38.8,6.364376,52,7.03,60,7.19,75,7.33,90,7.37,110,7.6,120,7.57,135,7.34,150,6.9,157.7,6.560675
14,38.2,6.477006,52,7.15,60,7.33,75,7.53,90,7.59,110,7.89,120,7.91,135,7.71,150,7.35,168.2,6.793566
16,37.8,6.530364,52,7.23,60,7.41,75,7.67,90,7.79,110,8.13,120,8.22,135,8.05,150,7.69,177.2,7.148534
20,37.6,6.5885,52,7.29,60,7.49,75,7.81,90,8.09,110,8.43,120,8.76,135,8.72,150,8.33,179,7.81119

Wind Speed	52°	60°	75°	90°	110°	120°	135°	150°
6	5.31	5.57	5.72	5.59	5.54	5.38	4.88	4.14
8	6.22	6.44	6.57	6.5	6.63	6.5	6.01	5.25
10	6.76	6.93	7.05	7.08	7.24	7.17	6.85	6.18
12	7.03	7.19	7.33	7.37	7.6	7.57	7.34	6.9
14	7.15	7.33	7.53	7.59	7.89	7.91	7.71	7.35
16	7.23	7.41	7.67	7.79	8.13	8.22	8.05	7.69
20	7.29	7.49	7.81	8.09	8.43	8.76	8.72	8.33

Wind Speed	Beat Angle	Beat VMG	Run Angle	Run VMG
6	43°	3.5	145.1°	3.58
8	41.2°	4.21	149.8°	4.55
10	39.6°	4.7	152.3°	5.37
12	38.8°	4.96	157.7°	6.07
14	38.2°	5.09	168.2°	6.65
16	37.8°	5.16	177.2°	7.14
20	37.6°	5.22	179°	7.81

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