Separate offshore forecasts from the beach
A marine forecast describes modelled conditions over an area. The shape of the coast, seabed, shelter and tide affect what reaches a particular break. Start with the official forecast and warnings, then ask someone qualified locally how those conditions usually translate at your chosen beach.
Read height, period and direction together
Wave height alone leaves out the spacing and direction of incoming swell. Compare the forecast fields together and watch how they change through the day. Do not turn a simple rule about period into a promise of wave quality: the beach and the swell have to work together.
Add the wind and the timing
Wind can change the surface and the experience of being on an exposed beach. Check the expected direction and strength, not only a sunshine icon. Look at your actual session window and the return journey rather than a daily summary.
Make an observation log
Record the forecast, the beach, the tide stage and what you actually saw from shore. Note whether an instructor moved the session and why. Over time, your own observations can make forecasts more meaningful, but they never replace local restrictions or an honest assessment of your ability.