A handy and simple tool to determine in a minimum time what is really needed as tug assistance, is the Bollard Pull Calculator which calculates in an approximate way the total required tug power for ships in various conditions of wind and current. This tool can be loaded as an app on the smart phone.
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A maritime pilot, marine pilot, harbor pilot, bar pilot, or simply pilot, is a sailor who maneuvers ships through dangerous or congested waters, such as harbors or river mouths. They are navigational experts possessing knowledge of the particular waterway such as its depth, currents, and hazards.