Port winch
- drum circumference = 3.3 2 m
- six twenty wraps of cable = 19.8 64 m which is also 2.5" width of cable on the drum
- drum width is ~ 40 " which is 96 wraps or 316 m of cable
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World Magnetic Model - 2019.0 Main Field Intensity
Magnetometer layback
= 434 m from AFT_GPS
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. This satisfies the required magnetometer layback of 3 times the length of vessel (3 x 143.4 = 430.2 m)