The mean between the great tropic tidal range and the small tropic range. The small tropic range and the mean tropic range are applicable only when the type of tide is semidiurnal or mixed.
Related Terms 
ALUM
Is an aluminum sulfate or filter alum. Acts in the range of 5.0 to 8.0 pH.

ISO SOLID CONTAMINANT CODE (ISO 4406)
A code assigned on the basis of the number of particles per unit volume greater than 5 and 15 micrometers in size. Range numbers identify each increment in the particle population throughout the spectrum of levels.

HARMONIC FUNCTION
Any real function that satisfies a certain equation. In its simplest form, as used in tide and tidal current predictions, it is a quantity that varies as the cosine of an angle that increases uniformly with time

HARMONIC CONSTANTS
The amplitudes and epochs of the harmonic constituents of the tide or tidal current at any place

HIGH WATER INEQUALITY
The difference between the heights of the two high waters during a tidal day

HIGH WATER
The maximum height reached by a rising tide. The height may be due solely to the periodic tidal forces or it may have super imposed upon it the effects of prevailing meteorological condi tions. Use of the synonymous term HIGH TIDE is discouraged.

HALFTIDE LEVEL
A tidal datum midway between mean high water and mean low water. Mean sea level may coincide with halftide level, but seldom does; the variation is generally about 3 centimeters and rarely exceeds 6 centimeters. Also called MEAN TIDE LEVEL.

HALFTIDE LEVEL
A tidal datum midway between mean high water and mean low water. Mean sea level may coincide with halftide level, but seldom does; the variation is generally about 3 centimeters and rarely exceeds 6 centimeters. Also called MEAN TIDE LEVEL.

ANTIFRICTION BEARING
A rolling contact type bearing in which the rotating or moving member is supported or guided by means of ball or roller elements. Does not mean without friction.

HARMONIC PREDICTION
Method of predicting tides and tidal currents by combining the harmonic constituents into a single tide curve, usually performed by computer.
