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        | frequent or continuous determination of position |  | 
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        | intersection of a sphere through its center |  | 
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        | primary great circle of a sphere, perpendicular to polar axis |  | 
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        | north-south reference line, usually a great circle |  | 
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        | 0 degree meridian of longitude |  | 
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        | angular distance from the equator |  | 
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 | Definition 
 
        | angular distance along a primary great circle, from the adapted reference point |  | 
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        | one nautical mile per hour |  | 
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 | Definition 
 
        | distance in nautical miles between two meridians at any given point of latitude |  | 
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        | direction of net movement of one place to another |  | 
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 | Definition 
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 | Definition 
 
        | speed intended to be made good |  | 
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 | Definition 
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 | Definition 
 
        | net speed form one point to another |  | 
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 | Definition 
 
        | direction vessel is facing |  | 
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        | direction of travel through water |  | 
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 | Definition 
 
        | directions in which a vessel is steered or intended to be steered |  | 
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