Measured Mile
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A measured mile is a precisely surveyed distance of exactly one nautical mile (1,852 meters or 6,076 feet) used by vessels to calibrate speed logs and measure maximum speed. It is identified by two pairs of shore-based markers (ranges) that, when aligned, indicate the start and end points of the mile.
Key Aspects of a Measured Mile:
Purpose: Primarily used for speed trials to determine how fast a vessel can travel.
Procedure: A ship travels at a steady speed on a specific bearing, aligning the first pair of markers to start timing and the second pair to end timing.
Accuracy: To account for current and wind, vessels often run the mile twice in opposite directions and take the average speed.
Markers: These are often towers or designated structures on shore that are illuminated at night.
Location: While often found near shipyards for testing new or repaired ships, they are marked on nautical charts for navigation use.
Key Aspects of a Measured Mile:
Purpose: Primarily used for speed trials to determine how fast a vessel can travel.
Procedure: A ship travels at a steady speed on a specific bearing, aligning the first pair of markers to start timing and the second pair to end timing.
Accuracy: To account for current and wind, vessels often run the mile twice in opposite directions and take the average speed.
Markers: These are often towers or designated structures on shore that are illuminated at night.
Location: While often found near shipyards for testing new or repaired ships, they are marked on nautical charts for navigation use.