Guide
Reading a tide table on the Georgia coast
Checked October 8, 2026 against NOAA Tides and Currents and NOAA’s National Ocean Service.
The Tides tile repeats NOAA’s predictions for the station nearest your town and, where there is one, what its gauge is measuring now. On this coast the tide is big, about seven feet twice a day, and it runs far up the rivers and through the marsh. This page explains what the zero is, the shape of the tide here, which station each town reads, which tables are worked out from another station, and how far the wind can push the water off the table.
Zero is not the bottom
Every height on the tile is measured from mean lower low water — MLLW — which NOAA defines as “the average of the lower low water height of each tidal day observed over the National Tidal Datum Epoch.” Because it is an average, many low tides fall below it: a prediction of −1.2 ft on a spring tide is not an error. A charted depth is also measured from MLLW, so a creek charted at 4 feet has less than that on a minus tide.
A big tide, twice a day
This is a semidiurnal coast: two highs and two lows a day, about twelve and a half hours apart, of nearly equal height. The range is the largest on the whole southeast coast; the concave shore between Cape Hatteras and Cape Canaveral funnels the ocean tide, and it peaks here. NOAA’s figure for each station is the great diurnal range, “the difference in height between mean higher high water and mean lower low water”: 7.50 ft at Fort Pulaski, 8.37 ft up the Skidaway River, 7.72 ft at Brunswick, 6.92 ft at Kings Bay. Twice a month, at the new and full moon, the spring tides run a foot or two more than that.
The tide also arrives late up the rivers and creeks. High water at Savannah comes 44 minutes after Fort Pulaski at the river mouth; at Darien, 68 minutes; on the Little St. Marys River, nearly three hours after Fernandina Beach. A table for the mouth is the wrong table for the landing upstream.
Which station each town reads
“Live gauge” means NOAA publishes the gauge’s measured level as it comes in; “prediction” means a table and nothing measured. The Savannah board reads nine stations and the Golden Isles board nine stations. The range is NOAA’s great diurnal range for that station; a dash means NOAA publishes no datum figure for it.
Savannah and the Georgia coast
| Town | Station | Range | Reading |
|---|---|---|---|
| Tybee Island | Tybee Light 8670892 | — | Prediction, worked from Fort Pulaski |
| Savannah | Savannah 8670681 | — | Prediction, worked from Fort Pulaski |
| Thunderbolt | Skidaway Institute, Skidaway River 8671086 | 8.37 ft | Prediction |
| Wilmington Island | Skidaway Institute, Skidaway River 8671086 | 8.37 ft | Prediction |
| Skidaway Island | Priest Landing, Wilmington River 8671315 | 7.91 ft | Prediction |
| Richmond Hill | Richmond Hill, Ogeechee River 8671489 | 5.21 ft | Prediction |
| Midway | Sunbury, Medway River 8672875 | 7.86 ft | Prediction |
| Sunbury | Sunbury, Medway River 8672875 | 7.86 ft | Prediction |
| Darien | Darien, Darien River 8675779 | — | Prediction, worked from Fort Pulaski |
| Sapelo Island | Old Tower, Sapelo Island 8675622 | 7.43 ft | Prediction, worked from Fort Pulaski |
The one live gauge on this board is Fort Pulaski, at the Savannah River entrance (8670870, range 7.50 ft), which no town reads as its own table but which the four worked tables above are made from, and whose measured level the tile shows beside them.
The Golden Isles
| Town | Station | Range | Reading |
|---|---|---|---|
| Brunswick | Howe Street Pier, Brunswick 8677406 | 7.72 ft | Prediction |
| St. Simons Island | St. Simons Light 8677344 | 7.20 ft | Prediction |
| Sea Island | Frederica River 8676743 | — | Prediction, worked from Fort Pulaski |
| Jekyll Island | Jekyll Island Marina, Jekyll Creek 8677832 | 7.39 ft | Prediction, worked from Fernandina Beach |
| Woodbine | Ceylon, Satilla River 8678466 | — | Prediction, worked from Fernandina Beach |
| Kingsland | Little St. Marys River 8720006 | 4.61 ft | Prediction, worked from Fernandina Beach |
| St. Marys | St. Marys 8679964 | 6.39 ft | Prediction |
| Cumberland Island | Crooked River, Cumberland Dividings 8679242 | — | Prediction, worked from Fernandina Beach |
The live gauge on this board is Kings Bay, on Cumberland Sound (8679598, range 6.92 ft), which the tile shows beside the tables.
Nine tables are worked out from another station
NOAA publishes two kinds of tide prediction. “Harmonic stations are stations with tidal harmonic constants and tidal datums. Tide predictions for harmonic stations are generated directly from the harmonic constants.” But “subordinate stations are historic stations which do not have tidal harmonic constants available”, and for them NOAA first makes “high/low tide predictions for a designated harmonic station, called the ‘reference station’; then time and height adjustments are applied to correct the high/low predictions to the tidal conditions at the subordinate station.”
Five tables on the Savannah board and on Sea Island are made from Fort Pulaski (8670870): Tybee Light, 10 minutes before it; Savannah, 44 minutes after at 1.14 times the height; Darien, 68 minutes after; the Old Tower on Sapelo Island, 15 minutes after; and the Frederica River behind Sea Island, 48 minutes after. Four on the Golden Isles board are made from Fernandina Beach, Florida (8720030): Jekyll Island Marina, Ceylon on the Satilla, the Crooked River, and the Little St. Marys River, where high water comes 2 hours 49 minutes after Fernandina’s at 0.71 times the height. NOAA adds that “subordinate stations only allow for the generation of high/low tide predictions, and heights will be relative to Mean Lower Low Water (MLLW)”. Nothing at those nine places is measured.
Why the water is not where the prediction said
NOAA is direct about what a tide table leaves out:
- “We can only predict the astronomical tides” — the pull of the Moon and Sun.
- “We cannot predict the effect that wind, rain, freshwater runoff, and other short-term meteorological events will have on the tides.”
The National Ocean Service: “Onshore winds may act to pile up water onto the shoreline, virtually eliminating low tide exposures”, and “strong offshore winds can move water away from coastlines, exaggerating low tide exposures.” This coast faces east, so a steady northeast or east wind is onshore and holds the water up, which is why a nor’easter on a spring tide floods the marsh roads, and the west wind behind a front is offshore and pulls it down.
How big: between October 1, 2025 and October 7, 2026, NOAA’s hourly heights ran away from the prediction at both gauges. At Fort Pulaski the water ran 3.0 feet above it and 2.3 below; at Kings Bay 3.3 above and 2.1 below. Against a seven-foot range that is less than the tide itself, but a three-foot push on top of a spring high is what puts the water over the bulkheads.
So read the tile this way. Where the board has a live gauge, the measured level is the answer and the prediction is a guide to when it will rise and fall. Where the town’s table is predictions only, treat the table as the start of the question and look at the wind forecast. And a hurricane’s storm surge is a different thing altogether; it is the weather service’s warnings, not the tide table, that speak to it.
Sources
- NOAA Tides and Currents, tidal datums — MLLW and the great diurnal range
- NOAA National Ocean Service, types and causes of tidal cycles — the semidiurnal tide
- NOAA National Ocean Service, what affects tides in addition to the Sun and Moon — onshore and offshore wind, river flow
- NOAA Tides and Currents, frequently asked questions — what a prediction can and cannot include
- NOAA Tide Predictions, help — harmonic and subordinate stations
- NOAA’s adjustments for the worked tables: Tybee Light, Savannah, Darien, Old Tower, Frederica River, Jekyll Island Marina, Ceylon, Little St. Marys River, Crooked River
- Measured water levels, the live gauges the boards read: Fort Pulaski, Kings Bay
- NOAA’s datums for each station, which give the great diurnal range: for example Fort Pulaski