Height
Set a minimum that is meaningful for the spot, then add a maximum if larger swells become unsafe or close out.
SwellOracle Academy · Advanced
Turn ocean signals into useful alerts.
A useful alert is not a universal promise of good surf. It is a personal filter that tells you when the ocean is worth checking more closely at one specific spot.
Start with the spot, not the number
Write down the exposure and the swell directions that actually reach your break. A threshold that works for an exposed beach may create noise at a sheltered bay.
Choose one or two nearby physical references and keep model points clearly labelled as context. An alert should be tied to a source and location you understand.
Build the first filter
Period
Use a minimum period to avoid repeated alerts for short wind sea when you are waiting for more organized swell.
Direction
Limit alerts to directions that can reach the beach instead of reacting to every large offshore reading.
Wind and tide
Use local wind direction and strength, plus rising or falling tide, to decide whether a swell signal is worth opening.
Refine after real sessions
Keep a short record of the alert, what the station reported, the wind and tide, and what you actually saw. Adjust one threshold at a time so you know what changed.
If alerts arrive too often, raise the period or narrow the direction before simply raising height. If good windows are missed, loosen one filter and observe again.
Too many alerts
The threshold may be too broad, the period too short or the source may be exposed to swell that your beach does not receive.
Too few alerts
The height, direction or period may be too strict, or the selected station may not represent the spot's exposure.
Alert looks good, beach is poor
Check wind, tide stage, current, local shelter and whether the station is measuring a different wave system.
Keep alerts as a prompt to check
An alert should open a decision process, not replace it. After receiving one, confirm the latest timestamp, compare wind direction and strength, check whether the tide is rising or falling, and review official warnings.
Over time, a personal alert becomes useful because it reflects your spot, your tolerance and the conditions you actually want to surf.
Practical takeaway
The best alert strategy is local and iterative: use swell as the signal, wind and tide as context, and real sessions as feedback.