Tide rarity
NOAA high/low predictions inside the chosen 7- or 30-day window are separated by type. Highs are ranked high-to-low and lows low-to-high. Percentile-like rarity is local to that station and window.
Every score is a shortcut back to the underlying data.
We use simple, inspectable calculations. The score helps rank where to look first; it never replaces an official warning, closure or local decision.
Daylight usefulness
Sunrise and sunset are calculated from the location coordinates and event date. Tidepooling favors low tides in daylight; photography favors extreme tides near sunrise or sunset.
Water anomaly
The newest NOAA observed water level is compared with the nearest same-datum astronomical prediction. Difference = observed − predicted. It is context, not a flood declaration.
Big-wave signal
Current NDBC significant wave height and dominant period create a viewing-interest signal. Because a buoy observation is current, the site does not reuse it as a future wave forecast.
Wildlife pulse
Recent public Cetacea and Pinnipedia observations within a bounded radius are counted as a reporting pulse. Observer effort means this is not an abundance model.
Official-alert override
NWS alerts are displayed separately and can suppress a positive “Worth the trip” presentation. We still never render “safe,” because absence of an alert is not proof of safety.
EXAMPLE, NOT A SECRET FORMULA
Tidepool score
35 + (local low-tide rarity × 40) + daylight bonus − current hazard-context penaltyThe exact component weights are published so a score is interpretable. When a component is unavailable, the UI says which component is missing rather than quietly awarding points.
Use the score as a filter, not an all-clear.Official warnings, local closures, surf conditions and access rules always take priority.