East Coast Footnotes

#6: Low water time difference is +2hr 47m. CAUTION: Predictions of the times of low water must be used with caution because of the peculiarities in the behavior of the tide at this location. The low tide may be practically at a stand for as much as 2 hours before or after the predicted times of low water.

#7: Tidal information only applies during low river stages.

#8: Values for the Hudson River above the George Washington bridge are based upon averages for the six months May to October, when the freshwater discharge is at a minimum

#9: In Almermarle and Pamlico Sounds, the periodic tide has a range of less than 0.5 foot.

#11: In Choctawhatchee and Perdido Bays the periodic tide has a range of less than 0.5 foot.

#12: At New Orleans the diurnal range of the tide during low river stages averages 0.8 foot. There is no periodic tide at high river stages.

#13: For places on the Pacific Coast, Click Here.

#14: Inside, in the various bays, except near the inlets, the periodic tide has a mean range of less than 0.5 foot.

#15: Spring Range is given instead of diurnal range.

#20: The time differences should be applied only to the higher high and lower low water times of the reference station.

#21: From Oak Hill southward in Mosquito Lagoon the periodic tide is negligible.

#22: In Indian River north of Palm Bay, in Banana River and in Banana Creek, the periodic tide is negligible.

#24: The periodic tide is negligable, at this location and above.

#25: Data is for low river levels. At high levels the tidal range is reduced.

#26: The periodic range of tide is negligible at this location.

#27: The periodic range of the tide is negligible inside Sugarloaf Sound.

West Coast Footnotes

#2: For places in the Carribbean Sea and Gulf of Mexico Click Here.

#4: These data apply only during low river stages.

#5: The Columbia River is subject to annual freshets. Short range predictions are available at local river forecast centers. The data for stations above Harrington Point apply only during low river stages.

There is a tidal influence along most of the length of the Columbia River. However, that influence becomes smaller at greater distances from the Pacific Ocean. We are able to provide predictions of the times and height of tides from the Columbia River Entrance to Harrington Point, Washington. Above Harrington Point, although there is still a tidal influence and we can predict the times of the high and low tides, the water levels experienced are more a result of freshwater flow in the river than the astronomical tides. It is for this reason that the heights of both high and low tides along the Columbia River, above Harrington Point, are set to a value of "0.0 feet".

#6: Station on the Canadian side are not avilable from this office.

#7: The low water seldom falls below chart datum.

#8: The data for La Conner apply only during low levels of the channel which usually oocur in midsummer. Low water seldom falls below the chart datum.

#9: Heights are referred to mean lower low water, the datum of soundings on National Ocean Service charts.

#10: Because of shoals, low water at this place is restricted from falling below half tide level outside the river entrance.

#11: A bore frequently occurs in Turnagain Arm just after low water. Under favorable conditions it is said to reach a height of 6 feet.

#12: Becasue of the shoal condition of the upper part of Knik Arm, the channel of Eklutna becomes preacticall a nontidal strem during the period when the height of the tide at Anchorage is less than 15 feet above mean lower low water.

#13: No low water falls below -2 feet.

#14: When the difference in height between lower high water and high high water at Nushagak Bay is less than 8 feet, reliance should not be placed on calculated corresponding tides at Black Rock because the tide there may actually be Diurnal.

#17: The slough in this area goes dry at low water stages of the tides. The mean high water depth is about 5 feet.

#18: Due to bottom configuration and depths at low water stages, a low water stand may occur at this location.

Pacific Islands Footnotes

#30: Except near times of the moon's quadrature when the range of tide is negligable, the high water occurs about noon and midnight and the low waters about 6am and 6pm.

Revised: 21 October, 2004