Maritides

App · August 2026 · Claude Code

A one-page tide viewer for Grand Manan Island, New Brunswick. Built to answer one question at a glance: is the tide coming in or going out, and when is the next high?

What it does

A big "coming in / going out" state with a countdown to the next high or low.
A 36-hour tide curve with every crest and trough labelled, and a NOW marker.
Every high and low for the next two weeks, day by day.
Three locations: North Head and Seal Cove on the island, plus Blacks Harbour at the mainland end of the ferry.
Metres and feet, always in Atlantic Time, no matter what time zone the phone thinks it is in.

It works offline

Predictions are computed in the browser from harmonic constituents baked into the page. Nothing is fetched at runtime, so once it has loaded it keeps working with no signal, which matters on an island where coverage is patchy. Open it once on wifi, add it to your home screen, and it opens like an app with no network at all.