Marigram: Tide Chart & Widget

Marigram provides accurate offline tide charts, official NOAA tide tables, and custom tide alerts for all 3,496 U.S. coastal stations. Track high and low water levels, moon phases, and marine weather forecasts directly on your phone—even when cell signal drops out at the pier, beach, or boat ramp. Key Features: 100% Offline Tide Predictions: Harmonic calculations run directly on your device using official NOAA constants, delivering instant access to coastal data without an internet connection. Live NOAA Gauge Comparison: Compare predicted heights against real-time water level readings from nearby acoustic and pressure gauges to spot wind-driven water or storm surge when online. Marine Weather Integration: View localized wind speed, swell, and sea conditions powered by the National Weather Service forecast right alongside your daily curve. Smart Activity Windows: Automatically scan the next 14 days to find the exact daylight, height, and duration windows for your specific coastal outing. Offline Tide Alerts: Schedule local notifications for upcoming high or low water, minus-tide mornings, and custom activity windows that trigger reliably without mobile reception. Home Screen Tide Widget: Monitor today's water curve and the exact countdown to the next turn of the tide at a glance. Plan Your Coastal Outings with Precision Instead of scrolling through raw numbers, tell Marigram what your trip requires. Set your preferred water height, daylight conditions, and duration to find the best two-week windows for: Tidepooling: Catch daylight minus tides when coastal pools are fully exposed. Clamming & Foraging: Identify the lowest low water cycles of the month. Kayaking & Boating: Check safe launch depths for boat ramps and shallow channels. Shore Fishing & Photography: Track moving water, solunar transitions, and golden-hour low-tide reflections. Complete Monthly Tide Almanac Browse a full month of coastal predictions on a single screen. Quickly spot seasonal king tides, daylight minus tides, monthly extreme highs and lows, and maximum tidal ranges. Tap any date for a detailed daily breakdown of high and low tide times alongside sunrise, sunset, and lunar phases. Built for the Water Switch effortlessly between three specialized display modes: high-contrast Chart Paper for bright midday sun, Night Watch for dawn patrol, and Red Light mode to preserve your natural night vision on the water. Customize units in feet or meters and toggle between 12-hour and 24-hour time formats. Tested Accuracy & Privacy In benchmark testing across 36 reference stations, Marigram's on-device harmonic engine matched official NOAA tide tables to within one centimeter for hourly heights and to the exact minute for high and low turning points. No user account is required, and all station data is pre-loaded so you never have to download individual regional packs. Data Sources & Disclaimer Harmonic constants and live gauge readings are sourced from the NOAA Center for Operational Oceanographic Products and Services. Wind and marine forecasts are provided by the National Weather Service. Marigram is an independent utility and is not affiliated with or endorsed by NOAA, the National Weather Service, or any government agency. Astronomical predictions do not account for local barometric pressure, wind, or storm surge. Designed for recreational planning only; do not use as a primary tool for marine navigation. Download Marigram today to carry reliable U.S. tide charts, lunar almanacs, and custom coastal alerts wherever the shoreline takes you.

Marigram 1.0: offline tide charts for 3,496 NOAA stations, low tide and king tide alerts, activity windows, almanac and home screen widget. Free, with a one-time option to remove ads.