GEMMA XPRESS: ORC Rating

GPH

724.5

OSN

704

LOA

7.798 m

Displacement

1782 kg

Triple-Number Ratings

Lower is faster

Triple Inshore

Low

0.6351

Medium

0.8606

High

0.9718

Triple Offshore

Low

0.8186

Medium

1.0498

High

1.1672

Boat Specifications

Dimensions

Length overall: 7.798 m
Beam: 2.52 m
Draft: 1.43 m
Displacement: 1782 kg
Crew weight: 385 kg
Wetted surface: 13.99 m²

Sails

Mainsail: 19.5 m²
Genoa: 14.81 m²
Spinnaker: 42.75 m²
Asymmetric spinnaker: 0 m²

Design

Type: EXPRESS
Builder: ALBIN MARINE
Designer: PETER NORLIN
Year built: 1978

Performance data

Polar CSV

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

6,42.3,3.988475,52,4.46,60,4.7,75,4.89,90,5.01,110,5.06,120,4.89,135,4.4,147.9,3.789301,150,3.71
8,41.5,4.713229,52,5.29,60,5.52,75,5.69,90,5.89,110,5.93,120,5.83,135,5.36,150,4.67,152.1,4.571348
10,41,5.286802,52,5.79,60,5.95,75,6.06,90,6.28,110,6.35,120,6.28,135,6.04,150,5.52,152.7,5.412904
12,39.2,5.484264,52,6.02,60,6.17,75,6.32,90,6.51,110,6.76,120,6.67,135,6.41,150,6.09,169.1,5.60105
14,39,5.545934,52,6.1,60,6.29,75,6.53,90,6.66,110,7.14,120,7.13,135,6.81,150,6.43,180,6.01
16,39.2,5.574593,52,6.14,60,6.34,75,6.7,90,6.91,110,7.4,120,7.57,135,7.26,150,6.8,180,6.35
20,40.9,5.675703,52,6.16,60,6.34,75,6.79,90,7.29,110,7.77,120,8.25,135,8.35,150,7.66,180,7.07

Wind Speed	52°	60°	75°	90°	110°	120°	135°	150°
6	4.46	4.7	4.89	5.01	5.06	4.89	4.4	3.71
8	5.29	5.52	5.69	5.89	5.93	5.83	5.36	4.67
10	5.79	5.95	6.06	6.28	6.35	6.28	6.04	5.52
12	6.02	6.17	6.32	6.51	6.76	6.67	6.41	6.09
14	6.1	6.29	6.53	6.66	7.14	7.13	6.81	6.43
16	6.14	6.34	6.7	6.91	7.4	7.57	7.26	6.8
20	6.16	6.34	6.79	7.29	7.77	8.25	8.35	7.66

Wind Speed	Beat Angle	Beat VMG	Run Angle	Run VMG
6	42.3°	2.95	147.9°	3.21
8	41.5°	3.53	152.1°	4.04
10	41°	3.99	152.7°	4.81
12	39.2°	4.25	169.1°	5.5
14	39°	4.31	180°	6.01
16	39.2°	4.32	180°	6.35
20	40.9°	4.29	180°	7.07

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°	4.46	5.29	5.79	6.02	6.10	6.14	6.16
60°	4.70	5.52	5.95	6.17	6.29	6.34	6.34
75°	4.89	5.69	6.06	6.32	6.53	6.70	6.79
90°	5.01	5.89	6.28	6.51	6.66	6.91	7.29
110°	5.06	5.93	6.35	6.76	7.14	7.40	7.77
120°	4.89	5.83	6.28	6.67	7.13	7.57	8.25
135°	4.40	5.36	6.04	6.41	6.81	7.26	8.35
150°	3.71	4.67	5.52	6.09	6.43	6.80	7.66