harbour-tide

Universal tide predictions for Sailfish OS — native Silica client with a local harmonic engine (no tide API: offline computation, forever).

Features

• 7-constituent harmonic engine (M2, S2, N2, K1, O1, P1, K2): h(t) = Z₀ + Σ Aᵢ·cos(ωᵢt + φᵢ), computed locally
• 16 known ports with realistic constants (Italy + London, New York, San Francisco, Tokyo, Sydney, Honolulu)
• Free city search: OpenStreetMap geocoding via Photon with offline fallback on the local dataset; constants are taken from the known port within 222 km, otherwise from a synthetic lat/lon estimate (labelled)
• "Nearest port" card highlighted when opening a searched city
• 24/48/72 h chart with high/low tides marked with times, tap for the height at a given point
• Moon phase and sunrise/sunset computed
• English by default, Italian and English (language selector in settings: English / Italiano / System; .qm catalogue in the app data dir)
• Saved preferences: language, preferred port (opened at startup and shown on the cover), unit (m/ft), chart range

Build

Requires the Sailfish SDK.

sfdk target install SailfishOS-5.0.0.62-aarch64   # or your device target
sfdk target use SailfishOS-5.0.0.62-aarch64
sfdk build            # produces the RPM in RPMS/
sfdk deploy           # installs on the connected device

Recommended targets: aarch64 (Jolla Phone 2026, Xperia 10 II/III), armv7hl (Xperia X, Jolla C), x86_64 (emulator).

Structure

src/                C++: main.cpp (language + translator), settings
                    (QSettings: language, preferredPort, unit, days)
qml/js/tides.js     harmonic engine (pure ES5, Qt 5.6 compatible):
                    constants, prediction, extrema, synthetic estimate,
                    local geocoding, moon, sun
qml/pages/          MainPage (ports + free city search), DetailPage
                    (canvas chart, events, nearest-port card, astro),
                    SettingsPage (language, unit, range, port)
qml/cover/          cover with preferred port and next tide
translations/       harbour-tide.ts (EN source), harbour-tide_it.ts
icons/              icons 86/108/128/172 (make_icons.py, harbour style)
rpm/                spec and desktop file (SailJail: Internet)

Configuration

File: ~/.config/harbour/tide/tide.conf (QSettings, persistent zone of the SailJail sandbox). Keys: language (system/en/it), preferredPort, unit (m/ft), days (1/2/3).

Known limitations

• Port constants are synthetic but realistic; the lat/lon estimate does not distinguish closed basins (Mediterranean) from open ocean.
• Accuracy of a real global model (FES2014/TPXO9): ~10–20 cm in open ocean; the engine is ready to receive grid constants.
• Not for navigation.
• Language is applied on app restart.

License

MIT