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Tide clocks don’t
really qualify as marine electronics, but I want to make amends for past
skepticism regarding the genre. My gripe was that the extra hand on any
tide clock (or watch) only tracks lunar orbit time, which may be the most
powerful constituent in a tide prediction formula but is only one of dozens.
For instance, in places where lunar declination is also a major factor,
like the U.S. Gulf Coast, there’s often just one high tide per day,
and a tide clock is nearly useless. It really takes a PC or plotter processor
to reliably predict tides everywhere to the minute. On the other hand,
to-the-minute accuracy is a bit of an illusion as tides change very slowly
near high and low, and for many of us on the Atlantic and northern Pacific
Coasts, those highs and lows are closely associated with the moon’s
orbit.
Ocean-Clocks’ clever
new localized design not only focuses on areas where lunar time works
well, it also gives you a sense of the tidal relationships in that area.
The Cape Cod version I tried made graphic sense of the relative tide at
20 Massachusetts stations from New Bedford to Provincetown, more than
making up for its plus/minus one hour maximum inaccuracy. Plus, with a
little figuring, it also tracked the moon’s passing. U.S. distributor
Windward Instruments offers these clocks in several case styles for 17
East Coast regions plus Washington’s Puget Sound, with the hunky
solid brass design shown costing $349.
Windward Instruments
Phone: (800) 210-0492. www.bellclocks.com.
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