Support

Tides Pro computes tides with a harmonic-analysis engine based on the global FES2022b model, validated against reference ports of the Spanish Hydrographic Institute (IHM) with a median error of about ±10 minutes on open coast. Inside rias and estuaries tidal-wave propagation is more complex and the error can be larger; the app tells you so at those ports.

A number from 0 to 120 summarizing the day's tidal range. Below 40 we speak of neap tides (small range), 40–79 of average tides, and 80 upwards of spring tides: bigger range, stronger currents and, usually, better fishing and shellfishing.

Tides, coefficient, the fishing index and all astronomy (sun, moon, eclipses) are computed on your device: they work with no coverage, on a boat or at the beach. Only the weather forecast needs a connection, as it comes from Apple Weather.

Tap the port name at the top and search among the 99 included ports of Spain and Portugal — or search any beach, cove or coordinate in the world: the app extracts the harmonic constants for the point you choose.

The watch app shows the tide right now (height, rising or falling, countdown to the next event), the day's curve and the coefficient, with watch-face complications that update by themselves as each high or low tide passes. It syncs automatically from the iPhone.

Very little. The countdown and progress bar are animated by the system itself without running the app, and data refreshes only at key moments. You can toggle it from the Maritime profile.

Email me the port, date and time and I will check it against official tables. Times are always shown in the local time of the selected port, not your device's — the most common source of confusion.