The exact tide,
at the exact moment

The tide at any point on the planet can be described as a sum of simple waves: the principal lunar (M2), the solar (S2), the lunar elliptic (N2), the diurnals (K1, O1)… Tides Pro extracts from the global FES2022b model — a 1/8° grid, about 12 km — the amplitudes and phases of 16 of those waves for your exact port, and sums them with astronomical nodal corrections to the minute. That is why it works offline: there is nothing to ask any server for.

Before publishing anything we compared the engine with the Spanish Hydrographic Institute's official tables at 52 reference ports, event by event: the median error was ±10.7 minutes in time and ±6 cm in height on open coast. The same engine generates this site's live tide strip — site and app always agree.

Inside rias and estuaries the tidal wave deforms as it travels through shallow water, and a global model cannot fully capture that local physics. At those ports the app warns you instead of faking a precision it does not have. We would rather you always know the ground you stand on.

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

The FES2022b engine is validated against reference ports of the Spanish Hydrographic Institute with a median error of about ±10 minutes on open coast. Inside rias and estuaries the error can be larger — and the app tells you, instead of hiding it.

Yes: tides, coefficient, fishing index and astronomy are computed on-device. Only the weather needs a connection (it comes from Apple Weather).

Yes. Tides Pro launches free with no ads.

Head to the support page: more answers and a direct line to the developer.