Heave, Heavy Sea, High Sea, High Tide, High Water: Word Origins, Descriptions of Coastal Features, Processes

In the current alphabetic series of word origins and physical descriptions of coastal features and processes, here are heave, heavy sea, higher high water, higher low water, high sea, high tide, high water, high-water line, and high-water mark.

Heave
A heave, in general, is any upward motion, especially a rhythmical rising. On a sea, the vertical rise of waves is called a heave.

Heavy Sea
One meaning of the common adjective heavy is being greater in quantity or quality than the average of its kind, such as having unusually great force or momentum. Applied to marine terminology, the word is used in the phrase heavy sea, which refers to a sea having high waves.

Higher High Water
The higher of the two high waters, or tides, occurring during a tidal day is called the higher high water.

Higher Low Water
The higher of the two low waters, or tides, occurring during a tidal day is called the higher low water.

High Sea
As a general term, high sea refers to the open part of the sea or ocean. More specifically, the term usually appears in the plural, high seas, and denotes the sea or ocean, that is, the continuous body of navigable saltwater in the world, lying outside the territorial waters of any country.

High Tide
The greatest height reached by the water during a rising tide is called high tide. Some scientific authorities regard this term as a nontechnical expression, the technical term being high water.

Worldwide, the average interval between successive high tides is 12 hours, 25.5 minutes. However, the intervals range from less than 12 hours to more than 14 hours. In fact, some places, such as Vietnam and the Caribbean, have only one high tide per day. (Barnes-Svarney, p. 400)

High Water
High water is synonymous with high tide, the first being more common in technical contexts, the second being more common in general usage.

High-Water Line, High-Water Mark
A line or mark on a seashore to which the waters usually reach at high tide, or high water, is called a high-water line or a high-water mark. The term generally refers to the line that marks the limit of the rise of medium high tides, not the maximum or minimum high tides that occur during certain times of the year.
____________________________

Barnes-Svarney, Patricia, ed. dir. The New York Public Library Science Desk Reference. New York: Stonesong Press-Macmillan, 1995.

Encyclopaedia Britannica Ready Reference 2004. CD-ROM. Encyclopaedia Britannica, 2004.

Merriam-Webster's Collegiate Dictionary. 11th ed. Springfield, Mass.: Merriam-Webster, 2006.

Merriam-Webster's Geographical Dictionary. 3rd ed. Springfield, Mass.: Merriam-Webster, 2007.

The Oxford English Dictionary. 2nd ed. Oxford, England: Clarendon Press, 1989.