Where the data comes from
Every number on the board comes from a free public feed, read live when you load the page and cached for 15 minutes. When a feed fails, the page says it could not check. It never fills the gap with calm water.
By region
| Region | NWS marine zones | NWS shore zones | Tides | Sea level gauge |
|---|---|---|---|---|
| Catalina | PZZ655 | CAZ087 | Avalon 9410079 | Los Angeles Harbor 9410660 |
| Channel Islands | PZZ650, PZZ655, PZZ673, PZZ676 | CAZ549, CAZ550 | Santa Barbara 9411340 | Santa Barbara 9411340 |
| San Diego | PZZ740 | CAZ043 | La Jolla 9410230 | La Jolla 9410230 |
| Santa Barbara | PZZ650, PZZ673 | CAZ349 | Santa Barbara 9411340 | Santa Barbara 9411340 |
| Malibu & Palos Verdes | PZZ655 | CAZ362, CAZ366 | Santa Monica 9410840 | Santa Monica 9410840 |
| Santa Barbara Is. & San Nicolas | PZZ676 | CAZ087 | Avalon (nearest station) 9410079 | Los Angeles Harbor 9410660 |
| San Clemente Island | PZZ745, PZZ676 | none covers it | Wilson Cove, San Clemente Island 9410032 | La Jolla 9410230 |
| Orange County | PZZ655 | CAZ552 | Newport Beach 9410580 | Los Angeles Harbor 9410660 |
| North County San Diego | PZZ740 | CAZ043 | La Jolla 9410230 | La Jolla 9410230 |
| Point Loma | PZZ740 | CAZ043 | San Diego 9410170 | San Diego 9410170 |
Each dive spot is matched to the marine zone it sits in, checked against the Weather Service’s own zone map; a spot on a line counts both zones. Marine zones: PZZ650 East Santa Barbara Channel, Pt Conception to Pt Mugu, incl. Santa Cruz Island; PZZ655 Inner waters, Pt Mugu to San Mateo Pt, incl. Catalina and Anacapa; PZZ673 Pt Sal to Santa Cruz Island and westward 60 nm, incl. San Miguel and Santa Rosa; PZZ676 Outer waters, Santa Cruz Island to San Clemente Island, 60 nm offshore; PZZ740 Coastal waters, San Mateo Pt to the border, out 10 nm; PZZ745 San Mateo Pt to the border, 10 to 60 nm, incl. San Clemente Island. Shore zones: CAZ349 Santa Barbara County SW coast; CAZ549 San Miguel and Santa Rosa Islands; CAZ550 Santa Cruz and Anacapa Islands; CAZ362 Malibu coast; CAZ366 LA County beaches; CAZ087 Catalina and Santa Barbara Islands; CAZ552 Orange County coast; CAZ043 San Diego County coast. San Nicolas and San Clemente Islands have no shore zone.
The forecast
Wind, swell and sea temperature
Open-Meteo marine and weather APIs (CC BY 4.0; marine data from DWD and others), hourly at every spot, four days ahead. A model of open water a few kilometres out, not of your cove.
NWS marine alerts and forecast text
National Weather Service Los Angeles/Oxnard and San Diego, from api.weather.gov (alerts) and the coastal waters forecast text on tgftp.nws.noaa.gov. A small craft advisory or worse on a spot’s zone makes it No-go.
NWS shore hazards
Coastal flood advisories, high surf advisories, beach hazards statements and rip current statements are issued on land zones, not marine ones, so they are read separately. Shown in bold; they do not change a verdict.
What the water is doing now
Buoys and shore stations
Every active NOAA NDBC station from Point Arguello to the border, including the Scripps CDIP wave buoys. Readings older than three hours are dropped. See them all.
Tides, and the sea against the tide table
NOAA CO-OPS tide predictions, plus measured water level minus prediction at the nearest gauge that measures (Avalon, Newport Beach and Wilson Cove are prediction-only). A tide table cannot show a Kelvin wave, warm El Niño water or storm surge; this can.
Water against normal
NOAA Coral Reef Watch daily 5 km sea surface temperature anomaly, against the 1985–2012 average for the date, via CoastWatch ERDDAP (noaacrwsstanomalyDaily). About a day behind.
Water clarity from space
NOAA CoastWatch VIIRS daily 4 km Kd490 and chlorophyll-a, about two days behind and blank under cloud. Feeds the visibility estimate, which never changes a verdict.
Algal bloom risk
C-HARM v3.1 nowcast (California Harmful Algae Risk Mapping, on NOAA CoastWatch ERDDAP, wvcharmV3_0day): the modelled chance of Pseudo-nitzschia above 10,000 cells per litre and of domoic acid above 500 ng per litre. A model, not a water sample; check CDFW’s health advisories and closures before eating what you take.
Hurricanes
National Hurricane Center active storms, Eastern Pacific only, within 1,800 nautical miles. Those are the storms that send long-period south swell up the coast.
Water quality, fish and the rules
Beach water quality
San Diego County Beach & Bay, Los Angeles County Public Health (covers Catalina, April to October), Orange County’s ocbeachinfo.com and Santa Barbara County’s ocean water quality service. An advisory or closure within 600 m makes a spot No-go. Nobody samples the offshore islands.
Fish
Research-grade iNaturalist observations near each spot, with photos credited to their photographers and descriptions from Wikipedia. Warm-water visitors count any verifiable iNaturalist observation between Point Conception and the border.
Protected areas
CDFW marine protected area boundaries and regulations, read from CDFW’s own pages; see About for how the maps are built.
What this is not
A planning aid, not a safety call. The thresholds behind Go, Marginal and No-go are rules of thumb that have not yet been calibrated against a season of dive logs. Read them and disagree.