Marine & Surf Forecast Tool
Check marine weather, wave height, swell period, wind direction, tide cycles, and water temperature across global coastal zones.
Lower Trestles
San Onofre State Beach, San Clemente, CA 92672
5-Day Coastal Marine Outlook
Multi-day groundswell progression, wind shifts, and tidal swing windows.
About this tool
How to use it
- Select your target coastal zone, marine sector, or famous surf break from the spot selector or search bar.
- Inspect current primary wave height, groundswell period (seconds), and swell compass direction.
- Verify local wind velocity, wind angle (offshore, cross-shore, or onshore), and tidal height curves.
- Review water temperature and recommended wetsuit neoprene thickness (e.g., 3/2mm vs 4/3mm).
- Switch between Imperial (ft, mph, °F) and Metric (m, kph, °C) units, and save spots to your favorite coastal dashboard.
Why it matters
Surfers, boaters, coastal anglers, and ocean kayakers need instant access to wave mechanics, swell periods, and wind orientations to evaluate ocean safety and optimal surf windows without wading through complex raw NOAA buoy tables.
When to use it
Use when planning dawn patrol surf sessions, checking open-water boating advisories, scheduling offshore sailing departures around tide changes, or assessing sea state conditions before swimming or diving.
Common questions
Why is swell period (seconds) more important than wave height?
Swell period measures the time interval between consecutive wave crests. Long-period groundswells (14 to 20 seconds) originate from distant, deep-ocean storms, packing vastly more energy, traveling faster, and creating much more powerful, organized breaking waves than short-period windswells (6 to 9 seconds).
What is the difference between offshore and onshore winds?
Offshore winds blow from the land toward the ocean, grooming the face of incoming waves to make them clean, smooth, and hollow for surfing. Onshore winds blow from the sea toward the shore, creating choppy, disordered surface conditions and causing waves to crumble prematurely.
How do tides affect breaking wave quality?
Tide changes alter the depth of water over shallow sandbars or reefs. High tide may cause waves to become 'fat' or backwash against cliffs, while low tide can cause waves to drain rapidly, producing hollow barreling conditions or shallow closing-out sections.