Long-running tide stations turn changing water levels into records that can be studied and predicted. Historically, many stations used a float inside a stilling well connected to a pen-and-paper recorder. Later systems punched readings onto paper tape for computer processing. These stations commonly sampled water levels every six minutes, but they required frequent maintenance and could take weeks to deliver usable data.
Modern stations use electronic sensors selected for local conditions. NOAA sites commonly use acoustic or microwave sensors, often with a pressure-based backup. Satellite communications can send water-level and meteorological observations soon after collection, making it possible to compare predicted tides with what the water is actually doing.
Tide predictions are calculated from repeating astronomical signals called harmonic constituents. Scientists derive the local amplitude and timing of those constituents from observations collected at a station, then combine them to predict future astronomical tides. Monitoring and prediction support navigation, fishing, recreation, coastal engineering, habitat work, and scientific research. Tide Guide brings provider predictions and available surrounding conditions into one station-centered view; it remains planning information rather than a substitute for official navigation or emergency guidance.
Source: NOAA Tides and Water Levels