Symonds Bay, Biorka Island, AK tide times
NOAA tide prediction station 9451468, 56.8567° N, 135.5200° W. Heights in feet above MLLW.
Today at Symonds Bay, Biorka Island, AK
Today's predicted high and low waters, sunrise and sunset for Symonds Bay, Biorka Island, AK load here from NOAA. Without JavaScript they cannot be shown: NOAA's own table for station 9451468 is at tidesandcurrents.noaa.gov. Everything else on this page is measured and does not change from day to day.
What the tide does at Symonds Bay, Biorka Island, AK
Across the 1411 high and low waters NOAA predicts here for 2027, high water averages 8.98 ft above MLLW and low water 1.56 ft — a mean range of 7.42 ft. Taking each day's higher high and lower low, which is the swing someone standing on the shore actually sees, the average is 9.71 ft.
On 93% of days in 2027 there are two high waters and on the remaining 25 days only one. Where there are two, they differ in height by 1.71 ft on average. Successive high waters are 12h 25m apart on average.
The largest daily swing of 2027 is 14.72 ft on 22 January 2027 and the smallest is 2.48 ft on 5 November 2027 , a factor of 5.9 between the biggest spring tide and the smallest neap.
Measured figures
| Mean high water | 8.98 ft above MLLW |
|---|---|
| Mean low water | 1.56 ft above MLLW |
| Mean range | 7.42 ft |
| Mean great diurnal range | 9.71 ft |
| Largest daily range in 2027 | 14.72 ft on 22 January 2027 |
| Smallest daily range in 2027 | 2.48 ft on 5 November 2027 |
| Highest predicted tide | 12.18 ft at 11:53 AM on 22 January 2027 |
| Lowest predicted tide | -3.17 ft at 8:21 AM on 5 July 2027 |
| Average gap between high waters | 12h 25m |
| Tidal pattern | semidiurnal (1.93 high waters a day) |
| Position | 56.8567° N, 135.5200° W |
| NOAA station id | 9451468 |
Every figure above is computed from NOAA's published predictions for station 9451468 for the whole of 2027 (365 days, 1411 tides), not from a regional average or an estimate.
What MLLW means here
Every height on this page is feet above MLLW — mean lower low water, the chart datum NOAA publishes tide predictions against. It is the average of the lower of each day's low waters, taken over a 19-year period, so zero here is neither the sea bed nor the average sea level: it is a level the water drops below regularly. At Symonds Bay, Biorka Island, AK, 180 of the 706 low waters predicted for 2027 — 25% of them — fall below zero, the lowest being -3.17 ft on 5 July 2027.
Practically: a chart showing 6 ft of water here means about 6 ft at a mean lower low water and about 15.7 ft at a mean higher high. Add the predicted height for the moment you care about to the charted depth.
Where these predictions come from
This is a subordinate station. NOAA does not run a separate harmonic analysis here; it takes the predictions for Sitka, AK, 24 km (15 miles) away and shifts them. High water arrives 15 min earlier than the reference station and low water 16 min earlier than it. Heights are the reference station's with -0.1 ft added at high water and 0 ft at low water.
Those constants are NOAA's own, published for station 9451468 (reference 9451600). They are why a subordinate station's table is never simply its neighbour's.
Daylight at this latitude
Symonds Bay, Biorka Island, AK sits at 56.8567° N. The longest day of 2027 here is 17h 51m of daylight on 21 June 2027; the shortest is 6h 45m on 21 December 2027 — a difference of 11h 06m.
Day lengths are computed with NOAA's published solar algorithm from the station's latitude and longitude. Clock times for sunrise and sunset are deliberately not printed here: they depend on the station's UTC offset, and this site takes that offset from NOAA's own answers rather than from a timezone table — so it is the live panel above, which has them, that shows the times.
Nearest other stations
- Golf Island, Necker Island, AK 11 km (6.8 miles)
- Sitka, AK 24 km (15 miles)
- Dorothy Cove, Necker Bay, AK 31 km (19 miles)
- Olga Point, Olga Strait, AK 41 km (26 miles)
- Whitestone Narrows, Neva Strait, AK 44 km (27 miles)
- Red Bluff Bay, AK 48 km (30 miles)
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