"It's firing everywhere except here" is one of the more confusing experiences in surfing, and it's usually not a mystery — it's a swell shadow, and it's entirely explainable by geography.
What actually blocks a swell
Swell travels in fairly straight lines across open ocean, which means anything solid sitting between the storm source and your local break can block part of it before it arrives. Islands, headlands, and even other stretches of coastline can all cast a "shadow" over a spot sitting behind them relative to a specific swell direction — while a neighboring spot with a clearer path to the open ocean receives the same swell at full strength.
Why this explains so many "flat here, firing there" days
Two spots a few miles apart can have completely different swell shadow profiles depending on what's positioned between them and the open ocean in a given direction. A spot that's wide open to a southwest swell might be almost entirely shadowed from a west swell by the same landmass, and vice versa — which is why the exact same storm can produce wildly different results at spots that seem geographically similar.
Why this is spot-specific, not swell-specific
A swell shadow isn't a property of the swell — it's a property of the relationship between a specific swell direction and a specific spot's local geography. That's why generic regional forecasts ("the coast is picking up swell") can be technically true while still being useless for predicting whether your specific spot will see any of it.
For more on how swell direction windows work at the spot level generally, see How to Read a Surf Forecast.
We check your spot's actual exposure, not the region.
Swell shadows are baked into how we score every spot — so you're not left guessing why "the coast is firing" but your break isn't.
See your spot