Castle Islands, Duncan Canal Tides Today
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Castle Islands, Duncan Canal runs a mean tidal range of about 12.9 ft. This month the highest water, 19.4 ft, comes on the afternoon of Nov 25, and the lowest, a -3.8 ft minus tide, on the evening of Nov 25.
| Low tide | 2:50 AM | 2.3 ft |
| High tide | 9:15 AM | 14.8 ft |
| Low tide | 3:43 PM | 3.0 ft |
| High tide | 9:35 PM | 13.7 ft |
Today on the water at Castle Islands, Duncan Canal
Today at Castle Islands, Duncan Canal: high tide at 9:15 AM (14.8 ft) and 9:35 PM (13.7 ft), low tide at 2:50 AM (2.3 ft) and 3:43 PM (3.0 ft). Sunrise is at 7:06 AM and sunset at 4:06 PM.
Forecast: National Weather Service point forecast for this location.
Where Castle Islands, Duncan Canal is
Castle Islands, Duncan Canal sits at 56.6433° N, 133.1520° W on Southeast Alaska's Inside Passage, about 9 mi southwest of Petersburg, AK. The station here is a historical NOAA reference station: a gauge measured the tide at this spot from 1972 until 2024, and NOAA still publishes harmonic predictions from that record. There is no live reading here today. The closest gauge measuring live water level is Port Alexander, Baranof Island (NOAA 9451054), 63.3 mi away, and high and low water here run on average about 4 min later than there. The nearest weather station is Petersburg, an airport reporting wind, visibility and sky cover, but no water temperature, 13.5 mi away.
The tide at Castle Islands, Duncan Canal
Castle Islands, Duncan Canal has a semidiurnal tide: two highs and two lows a day of about the same size, roughly 12 hours 25 minutes apart. This month's predictions average 1.9 high tides a day here. The mean range from lower low to higher high is 15.8 ft, and 13.4 ft between the average high and the average low, a very large tide, among the biggest in the United States. On an average day the higher high tops the lower high by 0.9 ft and the lower low sits 1.5 ft below the other low. For the water around it: Inside Passage tides are large and mixed semidiurnal, two highs and two lows a day with ranges of 12 to 20 ft that drive fast currents in the narrows.
About this station
- High tide reaches Castle Islands, Duncan Canal about 9.8 hours after the moon passes overhead. That lag is local, which is why high water does not line up with the moon.
Datum and source
Heights on this page are feet above mean lower low water (MLLW), the zero NOAA's nautical charts use for soundings. A predicted 0.0 ft low is the average of the lower low each day; a minus tide is water below chart datum, and a 2 ft high means 2 ft more water than the chart shows. NOAA fixes MLLW at Castle Islands, Duncan Canal from the 1983-2001 National Tidal Datum Epoch; mean higher high water is 15.8 ft above it and mean sea level 8.0 ft. The land survey datum NAVD88, the zero on topographic maps and flood maps, is 3.2 ft above MLLW here, so a water level on this page converts to NAVD88 by subtracting that amount. These datums are controlled from NOAA's Ketchikan, AK gauge. Source: NOAA CO-OPS station 9451321, established 1972, gauge removed 2024. The tide times and heights are NOAA's official harmonic predictions for this station; TidalMap republishes them daily and does not alter them.
Tide stations near Castle Islands, Duncan Canal
- Petersburg: 14.0 mi, tides about 16 min later
- Wrangell, Wrangell Island: 31.5 mi, tides about 11 min earlier
- Kake Harbor, Keku Strait: 35.1 mi, tides at about the same time
- Point St. Albans: 49.9 mi, tides about 22 min earlier
- Craig, Klawock Inlet: 79.8 mi, tides about 19 min earlier
TidalMapMonthly tide calendar
🌊 Biggest flood tides of the month at Castle Islands, Duncan Canal this month: Nov 7, Nov 8, Nov 9, Nov 10, Nov 22, Nov 23, Nov 24, Nov 25, Nov 26, Nov 27. These spring highs run the highest water of the month.
🔻 Lowest tides of the month at Castle Islands, Duncan Canal this month: Nov 6, Nov 7, Nov 8, Nov 9, Nov 10, Nov 11, Nov 12, Nov 22, Nov 23, Nov 24, Nov 25, Nov 26 …. These minus lows are when flats and bars dry out.
Best fishing times (solunar)
Major and minor solunar windows for Castle Islands, Duncan Canal, peak feeding activity is around the moon overhead/underfoot (majors) and moonrise/moonset (minors). Score is the day's activity coefficient (0–100).
| Day | Major windows | Minor windows | Score |
|---|---|---|---|
| Today 🌗 | 7:14–9:14 AM 7:39–9:39 PM | 12:30–2:30 AM 1:35–3:35 PM | 63 |
| Thu Nov 5 🌘 | 7:59–9:59 AM 8:24–10:24 PM | 1:59–3:59 AM 1:40–3:40 PM | 75 |
| Fri Nov 6 🌘 | 8:44–10:44 AM 9:09–11:09 PM | 3:26–5:26 AM 1:46–3:46 PM | 85 |
| Sat Nov 7 🌘 | 9:29–11:29 AM 9:54–11:54 PM | 4:52–6:52 AM 1:53–3:53 PM | 93 |
| Sun Nov 8 🌘 | 10:16–12:16 PM 10:41–12:41 AM | 6:18–8:18 AM 2:02–4:02 PM | 97 |
| Mon Nov 9 🌑 | 11:04–1:04 PM 11:29–1:29 AM | 7:43–9:43 AM 2:16–4:16 PM | 99 |
| Tue Nov 10 🌑 | 11:54–1:54 PM 12:19–2:19 AM | 9:03–11:03 AM 2:39–4:39 PM | 98 |
Predictions & observations: NOAA CO-OPS station 9451321. Solunar windows computed from the moon's position for this location. Times shown in the station's local time. Not for navigation.
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