Wadehour: Offline Tide Tables — Help and questions

Wadehour tells you when the water at a NOAA tide station drops below a height you choose, and for how long. It works the tides out on your phone, so opening a station needs no signal.

This page covers what the app does, what it cannot do, what it costs, and how to reach us.

What Wadehour does

Today

Pick a station and Today shows:

the next low tide, with its time and height, and how long until it;
whether the water is rising or falling right now, how high it is, and the next turns of the tide;
the next low-water window below your line;
today's tide curve, with a marker for now;
every high and low of the day.

Every height is in feet or meters above MLLW (mean lower low water, the zero on NOAA's tables). Every time is in the station's own time zone, with its abbreviation, whatever zone your phone is in.

Low-water windows

This is the main thing Wadehour is for. You set a line, such as "below 1.0 ft", and the Windows tab lists every stretch in the next 7 days when the predicted tide is below it. Each row gives:

the day, and the start and end times;
how long the window lasts;
how low the water gets, and when;
how much of the window is in daylight.

When the low only just reaches your line, the row is marked "Only just". On a windy day a window like that may not open at all.

You can narrow the list to daylight only, to weekends, or to windows of at least 15 minutes, 30 minutes or 1 hour. The share button on each row sends that one window as a line of text through your phone's share sheet. Where there is no share sheet, as in the Android app, it copies the line so you can paste it into a message.

With Wadehour Pro, a chip on the Windows tab sets how far ahead the list reaches: the next 7 days, 30 days, 90 days or 12 months. Wadehour remembers 7 or 30 days; 90 days and 12 months last until you close the app.

Setting your line

"Set your line" (from the Windows tab, or from Settings) is where you choose the height. You can type it, minus sign and all. Or you can start from a suggestion worked out for the station you have open:

Minus tides (below 0.0 ft MLLW);
the lowest tide this week;
the lowest tide this month;
a line that about half of this month's lows reach;
the National Park Service's 1.0 ft guide for tidepooling on the Olympic coast;
the Bureau of Land Management's 3.0 ft guide for headland passage on the Lost Coast.

As you change the line, the screen shows how many windows it gives you and when the next one is. If nothing this week reaches your line, it tells you the lowest tide coming and offers a line just above it. Your line applies at every station.

Tide curve

The Curve tab draws the tide day by day for the next 7 days (30 days with Wadehour Pro). It shows every high and low, and it marks the stretches below your line. Drag along the curve to read the height at any minute.

Sun and moon

Sunrise and sunset, moonrise and moonset, and the moon's phase at your station, for the next 7 days. With Wadehour Pro, "Show the next 30 days" extends the list.

Stations

Wadehour carries 1,245 NOAA harmonic reference stations. You can find one by:

its name;
its NOAA station id;
browsing by state;
the name of a place people actually go. A short list of beaches, parks and towns, almost all on the

Pacific coast (Copalis and Fort Bragg, for example), points you to the reference station that serves them. When you get there this way, the app says plainly that the times are for that station, not for your beach;

Near me, which lists the closest stations with their distance in miles. Wadehour asks for

your location only when you tap Near me, and your phone shows its own prompt the first time (on Android 12 and later it offers approximate location only; on iPhone and iPad you can turn Precise Location off in it). If you say no, everything else still works, and search by name, id or state still finds every station. To use Near me after saying no, allow location for Wadehour in your phone's settings.

Star a station to keep it in Favorites. Stations you have opened recently are listed too.

There is no default station, and no station is picked for you. The first time you open Wadehour it asks you to choose one.

With Wadehour Pro

The month table, for this month and the next 12 (from Today): every high and low of the

month, one row per day.

Tide alerts (Settings, then Tide alerts): a reminder of a tide you care about, such as a low

below your line, every low, every high, or the moment the water drops under a height you choose, at the time or up to 14 days before it. Your phone shows each alert as a notification, with Wadehour closed and after a restart. On Android it can arrive up to an hour late unless Wadehour is allowed exact alarms (see "How do I make sure alerts arrive?" below). The alerts screen says how alerts reach your phone.

Export (Settings, then Export, or "Add all to calendar" under the window list): low-water

windows as calendar events, and the month table as a spreadsheet. Where your phone offers a share sheet, the file goes through it. In the Android app the calendar or spreadsheet is copied as text instead, and the app tells you so, so you can paste it into a file or another app.

Further ahead: every low-water window up to 12 months ahead (the chip offers 30 days, 90 days

or 12 months), and the tide curve and the sun and moon times to 30 days.

How do I make sure alerts arrive?

Allow notifications. Your phone asks when you save your first alert (on Android 13 and later,

and on iPhone and iPad). If you said no on Android, tap "Allow notifications" on the alerts screen if it is there, or open your phone's Settings, then Apps, then Wadehour, then Notifications, and turn them on. On iPhone and iPad, open Settings, then Notifications, then Wadehour, and turn on Allow Notifications. Without them, alerts reach you only while Wadehour is open.

Allow exact alarms (Android), so an alert arrives at the minute it was set for. On Android 14

and later this is off until you turn it on, and an alert may come up to an hour late. On the alerts screen, the Timing row says "Exact" or "May be up to 1 h late"; tap "Open Alarms & reminders" and turn it on for Wadehour. On most phones the same switch is in Settings, then Apps, then Special app access, then Alarms & reminders. iPhone and iPad have no such setting. There, a Focus or Scheduled Summary can hold notifications back: add Wadehour to the Focus's allowed apps, and in Settings, then Notifications, then Wadehour, choose Immediate Delivery.

Open Wadehour now and then. Your phone holds up to 64 of Wadehour's alerts at a time, lined up

over the next 30 days, and Wadehour adds more each time it opens. The alerts screen says how far ahead they are set. With a plan, alerts are set up to its renewal date. Open Wadehour after it renews, and the next ones are set.

Battery savers on some Android phones hold notifications back. If alerts come late even with

exact alarms on, let Wadehour run without battery limits in your phone's settings.

Settings

In Settings you can:

switch between feet and meters;
change your line, and turn Daylight only on or off;
choose a light theme, a dark theme, or match your phone;
see what stays free, and open Wadehour Pro, Tide alerts and Export;
read "Sources and datum", which says where every number comes from;
open the privacy policy;
erase everything Wadehour has stored.

How accurate is it

Wadehour predicts the astronomical tide from NOAA's published harmonic constants. It does this on your phone and never looks anything up.

A test in the app's test suite checks the first 120 highs and lows of 2026 at four stations: San Francisco (9414290), Boston (8443970), Pensacola (8729840) and Seattle (9447130). All 480 fall within 2 minutes and 0.05 ft of the predictions NOAA publishes, and each one is correctly called a high or a low.

Window start and end times are worked out from the same curve. They have not yet been checked against NOAA in a test of their own, so we claim no figure for them.

Wind, air pressure and river flow can hold the water a foot or more above or below the prediction. A window is a prediction, not a promise of dry ground. Wadehour never says a beach, a crossing or a route is safe or open. Check conditions where you are.

What Wadehour cannot do

Some of these were choices we made. Others are limits of the platform the app is built on. Either way, we would rather tell you here than have you find out on the beach.

No currents. Wadehour predicts how high the water is, not how fast or which way it moves.
No weather, and no live water levels. It never reads a gauge or a forecast, so it cannot see

a storm surge.

No subordinate stations. Only NOAA's 1,245 harmonic reference stations are included. A cove,

bay or inlet between them can run an hour or more behind the nearest one.

Not for navigation. It knows nothing about depths, charts or routes. Never use it to decide

whether a boat, a crossing or a route will clear.

No map. Maps need a network connection, so you find stations by name, id, state, place or

Near me.

No home-screen widget, no Apple Watch app, and no CarPlay or Android Auto. We have not built

them and do not plan to.

Alerts are only as punctual as your phone allows. Tide alerts (part of Wadehour Pro) can come

up to an hour late on Android unless exact alarms are allowed, and not at all while notifications for Wadehour are off. Never rely on an alert alone for a tide you cannot miss.

US stations, mostly. These are NOAA's stations. A few are outside the US (in Mexico, Bermuda

and Panama, among others) because NOAA publishes them, but Wadehour has no tide data for anywhere else in the world.

Does it work without signal?

Yes. Every station's constants are built into the app, and every prediction is worked out on the phone. Opening a station, listing windows and drawing the curve all work in airplane mode.

Buying Wadehour Pro, or restoring it, needs a connection, because Google Play, or the App Store on iPhone and iPad, takes the purchase. If you have Pro, it keeps working with no signal.

If you use Wadehour in a web browser rather than from a store, open it once with a connection so your phone can keep a copy. After that it opens without one. Wadehour Pro is not sold in a web browser.

What it costs

What does Wadehour cost? The download is free, and so is everything in the list below, with no ads and no account. Wadehour Pro, sold through Google Play and, on iPhone and iPad, the App Store, costs $19.99 a year or $2.99 a month (US prices; the store shows yours before you confirm). There is no lifetime or weekly plan. On Android you can try Pro free for a week first, with no card. On iPhone and iPad the free week is Apple's 1-week free trial of the yearly plan (see below).

What stays free

This list is built into the app and printed in Settings, word for word. Nothing on it will be taken away or put behind a payment, now or in any later update:

Search 1,245 NOAA tide stations
Today's highs and lows and tide curve, at any station
Today's sunrise, sunset, moonrise, moonset and moon phase
Feet or meters, with NOAA's source and datum on screen
Every tide worked out on your phone, with no signal and no account
Your next window below your line, how many more come in 30 days, and today's curve shaded below

your line

The window list, tide curves and sun and moon for the next 7 days, at any station
Share any window as one line of text

What does Pro add?

Every low-water window up to 12 months ahead; the tide curve and the sun and moon times beyond the next 7 days, up to 30; the month table, for this month and the next 12; tide alerts on your phone, even with Wadehour closed; and export of windows for your calendar and of the month table for a spreadsheet. See "With Wadehour Pro" above.

How does the free week work?

On Android:

One tap opens Pro for 7 days, with no card and no purchase. Wadehour offers it under your own

windows on the Windows tab, once, and on the Wadehour Pro screen: Settings, then Wadehour Pro, then "Try Pro free for 7 days".

Nothing is charged and nothing renews when the week ends. From day 5, Today shows one line with

the date the week ends, which you can dismiss.

When the week ends, Pro locks again. Your stations, your line and your settings stay as they are,

and everything free keeps working. Your alerts are kept, but they stop arriving until you have Pro again.

The free week is held by the app on this phone, so Google Play has no record of it.

On iPhone and iPad, the free week is Apple's 1-week free trial of the yearly plan, for new subscribers. It starts on the Wadehour Pro screen, and the yearly price is charged to your Apple Account when the week ends, unless you cancel at least 24 hours before it ends.

Am I charged anything?

On Android, only if you choose a plan on the Wadehour Pro screen and confirm it in Google Play's own payment sheet. The yearly plan is charged when you confirm, and every year after, until you cancel. The monthly plan is charged when you confirm, and every month after, until you cancel. The free week never turns into a plan by itself.

On iPhone and iPad, only if you choose a plan on the Wadehour Pro screen and confirm it in the App Store's own purchase sheet. If you start Apple's free trial, the yearly price is charged to your Apple Account when the week ends, then every year. Otherwise the yearly or monthly price is charged to your Apple Account when you confirm, then every year or month. Either way it renews until you cancel at least 24 hours before the end of the current period.

Cancelling

To cancel, in two taps: in Wadehour, open Settings and tap your Wadehour Pro row (1), then tap "Manage or cancel in Google Play" (2), or on iPhone and iPad "Manage or cancel in Settings". That opens your subscription in Google Play, or Apple's own subscription page, where you cancel. There is no screen of ours in between, no offer to talk you out of it, and nothing to fill in.

You can also cancel from Google Play directly: open the Play Store, tap your profile picture, then Payments & subscriptions, then Subscriptions. Choose Wadehour and tap Cancel. On iPhone and iPad, open your device's Settings, tap the name at the top, then Subscriptions.

Renews automatically until you cancel. Cancel any time in Google Play or the App Store (on iPhone and iPad, at least 24 hours before the end of the current period to stop the next charge), and Pro stays on until the end of the period you paid for. Then Wadehour goes back to free, with everything on the free list still working. Your alerts are kept for when you come back, but they stop arriving.

Refunds

Refunds come from the store that took the payment, under its own refund policy; we never see your card. On Android, ask through Google Play's refund page: https://support.google.com/googleplay/answer/2479637

On iPhone and iPad, ask Apple: https://reportaproblem.apple.com

Restoring

If you reinstall Wadehour or move to a new phone using the same Google account, or on iPhone and iPad the same Apple Account, tap "Restore purchases" on the Wadehour Pro screen. Pro comes back for as long as your plan runs. A subscription bought in one store does not carry over to the other.

Uninstalling

Uninstalling Wadehour (on iPhone and iPad, deleting it) does not cancel a subscription. Cancel it in Google Play, or in the App Store, first.

Your data, and getting it out

Everything you set in Wadehour lives on your phone: your favorite stations, your recent stations, your line, your alerts, your units and your theme. There is no account. No ads and no usage tracking. We have no server holding a copy. If your phone backs up to your Google account, Android may include these settings in that backup and bring them back when you reinstall; that copy is Google's, under your account, and we cannot see it. On an iPhone or iPad with iCloud Backup on, iOS may include them in that backup and bring them back if you restore the device from it; that copy is in your iCloud account, under Apple's terms.

To know whether you have Wadehour Pro, the app asks RevenueCat, its billing service, soon after it starts. That sends a random app user ID and basic app and phone details (on iPhone and iPad, also Apple's identifier for vendor, a random ID iOS gives one developer's apps on a device), and your purchase if you buy, never your stations, your line or your location. The privacy policy says exactly what goes.

Exporting. Any window can be shared as a line of text with the share button on its row. If your phone has no share sheet, the line is copied so you can paste it. With Wadehour Pro, Export makes calendar events of your windows and a spreadsheet of the month table, shared or copied the same way.

Because what Wadehour stores is a handful of settings, the quickest way to carry them to a new phone is to star the same stations and set the same line there.

Erasing. Settings → Your data → Erase everything. The app first tells you exactly what will go, then asks you to confirm. Erasing cannot be undone. Uninstalling Wadehour (on iPhone and iPad, deleting it) removes its data too. Neither reaches a copy in your phone's own backup, and neither cancels a subscription.

Updates keep your favorites and settings.

Common questions

Why does it say "Times are for Westport, not for Copalis Beach"? You searched for a place that has no NOAA station of its own, so Wadehour opened the nearest reference station that serves it. The tide at your beach can run earlier or later than at that station.

Why is a window marked "Only just"? The low barely gets below your line. A little wind or high pressure can keep the water above it.

Why don't I see any windows? Your line may be lower than any tide in the next 7 days. Or Daylight only, Weekends or a minimum length may be hiding them. Windows offers a line that the coming lows do reach, and "Set your line" names the lowest tide this week.

Why do the times not match my phone's clock zone? Times are always shown in the station's time zone, with its abbreviation, so a Hawaii station reads in Hawaii time even if your phone is in California.

Where does the data come from? From NOAA CO-OPS harmonic constants, which are public domain. They were taken from the @neaps/tide-database package, which repackages them. The date they were retrieved is shown in Settings, and the full sources and licences are under Settings → Sources and datum.

Is this an official NOAA app? No. Wadehour uses NOAA's public data, but it is not made by or connected with NOAA.

Who we are

Wadehour is made and published by Chibu LLC, an independent developer. We are not a government agency and not connected with NOAA. We do not run a server for the app, so we cannot see your stations, your line or anything else you do in it.

Questions, a station that looks wrong, a question about a purchase, or a place you would like added to the search: write to support@chibuapps.com. If you tell us the station and the date and time you were looking at, we can check it against NOAA's own predictions.