Forecasting
Offshore swell — days 1–8
Copernicus Marine Service combines satellite observations with numerical ocean models to deliver wave height, swell partitions, and sea state. It is the backbone of our offshore swell picture for the first eight days of the forecast before longer-range wave guidance takes over.
Extended swell — days 9–16
NOAA GFS-Wave provides publicly available wave model output. For extended 16-day forecasts, we use 3-hourly wave fields from this source and blend them with Copernicus from day 9 onward. NOAA data is used with attribution and without implying NOAA endorsement.
Near-term wind — days 1–5
OpenWeather supplies 3-hourly 10 m wind, temperature, and weather codes. We use this for the first ~five days of each forecast — cross-shore wind and local weather matter as much as swell height in the lineup. Weather data © OpenWeather.
Extended wind — days 6–16
For days beyond OpenWeather's ~5-day window, we use NOAA GFS atmospheric model output — 10 m wind speed and direction at 3-hourly steps — to carry wind forecasts through the full display horizon.
Tides — up to 16 days
Marea provides high-resolution tidal surfaces and coastal water levels. Reliable highs, lows, and tidal stages help keep dawn patrol and afternoon sessions inside realistic windows at reef and beach breaks.
Seafloor depth for spot physics
The General Bathymetric Chart of the Oceans (GEBCO) publishes a continuously updated global bathymetric grid. Shelf geometry, channels, and underwater slopes steer how swell refracts and shoals, so high-quality bathymetry is non-negotiable for spot-specific ratings.
Water temperature
Sea-surface temperature comes from NOAA's GHRSST when available, with Copernicus SST as a supplementary source where configured. If no reliable reading is available, the water-temperature row is omitted from the forecast display.
Community-built coastlines & places
OpenStreetMap is the collaborative map of the planet: coastlines, points of interest, paths, and infrastructure maintained by thousands of contributors. We lean on OSM where open geographic context improves orientation without locking you into proprietary basemap stacks.
Enterprise-grade basemaps
Esri's ArcGIS platform delivers authoritative cartography, imagery, and spatial services used by governments and utilities worldwide. Where our interface calls for polished basemaps and geographic scaffolding, ArcGIS helps the experience feel as serious as the forecast underneath.
Our physics-assisted pipeline ingests each spot's orientation and bathymetric footprint, then weighs swell energy, period direction, local wind, and tidal stage to produce the surf rating you see on the dashboard.
Offshore swell (height, period, direction partitions), near-term and extended wind, tide stage, and mapped bathymetry / coastline context feed the model. Provider roles are listed in the sections above.
Shelf depth, channels, and underwater slopes from bathymetry shape how swell shoals and refracts toward each break. We gate incoming swell by direction and exposure relative to that coastal geometry, so energy that is shadowed or poorly aligned with the local seabed contributes less to the rating than swell that can reach the pin cleanly.
Session ratings combine swell relevance, wind, and tide into a scanable score per timeslot. Colours on the dashboard are quality cues for that score — not guarantees that conditions will match on the day. Always confirm with the underlying swell, wind, and tide panels. For a practical walkthrough, see How to read a forecast.
Forecasts refresh as upstream model runs become available. Grids are not beach cameras: sandbars move, local wind can differ from the nearest cell, and breakthrough or shutdown days still happen. Use SURF NEXT as decision support alongside your own judgement and local knowledge.
Attribution: Weather data © OpenWeather. Wave and extended wind data from NOAA / National Weather Service (not an endorsement by NOAA). Copernicus Marine Service data © EU Copernicus Marine Service.
Forecasting surf will always involve judgement calls; these partners supply the observational and model rigour that keeps those calls honest. For legal notices about using SURF NEXT, see our Terms of Service and About pages.