Surf guide
Wave height and direction: why the same swell can feel different
Two beaches can see the same offshore swell and produce completely different surf. Height describes energy at the measurement point; direction decides whether that energy can enter a coastline, wrap around a point or miss a beach entirely.
Height changes with exposure
A four-foot offshore reading is not a universal beach size. Exposed reefs, submarine canyons and open beaches can amplify energy, while bays, islands and headlands can block it.
That is why SwellOracle treats height as a starting signal. The number becomes useful when paired with direction and period.
Direction controls access
Swell direction is the route the energy travels from. A beach facing southwest may react strongly to southwest swell and barely notice northwest energy. Another beach nearby can behave in the opposite way.
Direction also explains why long-period swells sometimes appear at protected points while shorter-period swell does not wrap in.
Use alerts with local thresholds
The best alert threshold is local. A beach that only works on west swell should not use the same trigger as a beach that receives south swell.
Start with conservative height and period values, watch a few events, and adjust after comparing the alert history with what actually happened at the coast.
Practical takeaway
Height tells you how much energy exists. Direction tells you whether your coast can use it.