ShellFinder scores each beach from 0 to 100 every hour by combining seven real-time factors. We pull live data from NOAA tide stations, Open-Meteo weather forecasts, and astronomical moon phase calculations — then run it through a shelling-specific scoring model.
Plus a combo bonus when post-storm conditions align with low tide — the perfect shelling day scores higher than the sum of its parts.
Low tide = more beach = more shells.
Low tides expose sandbars and beach that's normally underwater. The lower the tide, the more ground you can walk. Negative tides (below average low water) are the holy grail — they reveal shells that haven't seen daylight in weeks. We track live NOAA tide predictions for the station nearest each beach.
Onshore winds push shells toward the beach.
Wind direction matters more than speed. Wind blowing from sea to shore drives shells onto the beach; offshore wind pulls them back out. Each beach faces a different direction, so we score wind relative to each beach's orientation. We also look at the past 24 hours — sustained onshore wind is better than a brief gust.
Post-storm = the best shelling of the year.
Storms and fronts churn the seabed and dump fresh shells onto beaches. The day or two after a front passes is legendary. We detect recent storm activity from precipitation, wind gusts, and pressure changes in the weather data. If a storm just passed and the tide is low, our combo bonus kicks in — that's the perfect shelling day.
Cooler months tend to beat warmer ones.
Winter and early spring are usually prime shelling season. Frequent fronts stir the water, tides swing more extremely, and water clarity is better. Summer brings calmer water and fewer fronts to drive shells ashore — and on many coasts, runoff buries shells in sediment. We weight the calendar based on these patterns.
New and full moons create the biggest tides.
The moon's gravity drives the tides. During new and full moons, the sun and moon align, producing spring tides — extreme highs and lows. These extra-low tides expose more beach. Quarter moons produce weaker neap tides. We calculate the exact lunar phase for each forecast hour.
Sunrise beats midday by miles.
Early morning means fewer people have walked the beach. Shells found at sunrise haven't been picked over. We score sunrise and early morning highest, sunset slightly lower, and midday lowest. On popular beaches, the difference between 6 AM and 10 AM is dramatic.
Moderate waves are the conveyor belt.
Waves carry shells from the seabed onto the beach. Too calm and nothing moves. Too rough and shells break or it's not safe to wade. The sweet spot is moderate surf — enough energy to transport shells, not enough to smash them. We look at recent wave conditions to gauge this.