Search results
Results from the WOW.Com Content Network
Nautical mile: Length: Rhumb: Angle: The angle between two successive points of the thirty-two point compass (11 degrees 15 minutes) (rare) [1] Shackle: Length: Before 1949, 12.5 fathoms; later 15 fathoms. [2] Toise: Length: Toise was also used for measures of area and volume Twenty-foot equivalent unit or TEU: Volume: Used in connection with ...
A sailor and a man on shore, both sounding the depth with a line. Depth sounding, often simply called sounding, is measuring the depth of a body of water. Data taken from soundings are used in bathymetry to make maps of the floor of a body of water, such as the seabed topography. Soundings were traditionally shown on nautical charts in fathoms and
A nautical chart or hydrographic chart is a graphic ... echo sounding is used for measuring the seabed in the open sea. When measuring the safe depth of water ...
A nautical chart will always explicitly indicate the units of depth used. [17] To measure the depth of shallow waters, boatmen used a sounding line containing fathom points, some marked and others in between, called deeps, unmarked but estimated by the user. [18]
Used mainly to determine the minimum water depth for safe passage of a vessel and to calculate the vessel's displacement (obtained from ship's stability tables) so as to determine the mass of cargo on board. Draft, Air – Air Draft/Draught is the distance from the water line to the highest point on a ship (including antennas) while it is ...
Technical developments over the years improved surveying methods and the accuracy of the charts. For depth determination, methods of measuring depth from a moving ship were developed, as well as "sweeping", dragging a horizontal line across an area to detect hazards that might be missed by individual soundings. [24]
A chart datum is the water level surface serving as origin of depths displayed on a nautical chart and for reporting and predicting tide heights. A chart datum is generally derived from some tidal phase, in which case it is also known as a tidal datum. [1] Common chart datums are lowest astronomical tide (LAT) [1] and mean lower low water (MLLW).
Nautical charts are generally originally published by government agencies such as the U.S. National Oceanic and Atmospheric Administration, and are now provided in both print form and digital for use in chartplotters. nautical mile A unit of length corresponding to approximately one minute of arc of latitude along any meridian arc. By ...