An electronic communications or direction finding system which uses Very High Frequency radio waves. VHF radios are the most common communications radio carried on boats, but their range is usually limited to line of sight between the transmitting and rec ...

A naval rank next below that of admiral.

Vessel Identification System.

Uncharted navigational danger that has been reported but has not been verified by survey.

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Precipitation falling from a cloud, usually in wisps or streaks, but evaporating before it reaches the ground.

Temperature to which absolutely dry air would have to be brought in order for it to have the same density as moist air, considered at the same pressure.

Is a measure of resistance to deformation, or reluctance to be squeezed out a bearing. Indicates the internal friction of a fluid. Viscosity in normal lubricants is reduced as temperature increases

Is a measure of the rate of change of viscosity with temperature. Oils with high VI have low viscosity changes.

The greatest distance at which it is just possible to see and recognize with the unaided eye (1) in the daytime, a prominent dark object against the sky at the horizon, and (2) at night, a known, preferably unfocused, moderately intense light source.

General term for an instrument used to make direct measurements of visual range or measurements of the physical characteristics of the atmosphere which determine the visible range.

The amount of visible light that passes through the glazing material of a window, expressed as a percentage.

The visible portion of the electromagnetic spectrum with wavelengths from 0.4 to 0.76 microns

Electromagnetic radiation lying within the wavelength interval to which the human eye is sensitive, the spectral interval from approximately 0.4 to 0.7 microns (4000 to 7000 angstroms). Bounded on the short-wavelength end by ultraviolet radiation and on t ...

A fix taken by visually observing the location of known landmarks.

The maximum distance, usually horizontally, at which a given object or light source is just visible under particular conditions of transmittance and background luminance.

Namely. Used in tariffs to specify commodities.

Very Large Bulk Carrier (over 180,000 DWT)

Very Large Crude Carrier (between 160,000 - 320,000 DWT)

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