channel islands · live forecast
Excellent at mid reef — Drop in immediately. swell dropping and tide rising; small swell, minor bottom effect.
Depth · pick where you'll be
visibility right now per tier
Forecast
Now
WED, MAY 20, 3:00 PM
Viz
103 ft
63–125
Condition
Excellent
Conf
6%
Swell
2.6 ft
9 s W
Wind
9 mph
SW
Tide
-0.4 m
incoming
Rain
—
dry
Bottom motion
0.26 m/s
stirring
Chl-a
0.45
mg/m³
Reasoning
Three forces push visibility down — turbidity, runoff, biology. One pulls it back up — clearing. Here's how each is contributing right now, and how it changes over the next five days.
high positive · impact
Conditions improving.
Swell has been declining and tide is incoming, bringing cleaner offshore water into the site. Visibility should be improving.
Next five days
How fast the system is moving back to clear. Settles when swells drop, rain stops, and incoming tide brings cleaner offshore water in.
low · impact
Swell stirring the bottom.
2.6 ft, 9-second W swell is not significantly disturbing the seafloor at 14 m.
Next five days
When swells reach the seafloor, they kick sediment back into the water column. Long-period swells reach deeper than short-period chop.
negligible · impact
Rain pushing dirt offshore.
No significant recent rain or streamflow anomaly across no nearby sources.
Next five days
Rain carries freshwater, sediment, and dissolved matter from rivers, lagoons, and storm drains. Plumes can degrade visibility for days after a storm.
negligible · impact
How green the water is.
Clear, low-chlorophyll water — latest satellite chlorophyll-a 0.45 mg/m³; 171 h old.
Next five days
Phytoplankton blooms make water green and reduce clarity. Tracked via satellite chlorophyll-a and Kd(490). Cloud cover lowers confidence here.
Water column
Surf zone
0–10 ft
Shallow reef
10–30 ft
Mid reef
30–60 ft
Deep
60–100 ft
Below 100 ft
100–150 ft
— surface
Below the bottom-stress zone the water clears blue, even on a swell day. Surf zone is always limited by breaking-wave turbidity.
WRI
0.21
turbidity (primary tier)
Plume
0.00
runoff
Green
0.00
biology
Clearing
0.95
recovery
V_h(depth) = V_max · tier_mult(depth) · exp(−B)
B = 0.55·WRI(depth) + 0.50·plume + 0.35·green − 0.45·clearing
Model physics-0.3.0 · confidence 6% · read the long form
{
"wave_source": "openmeteo-marine",
"wave_status": "ok",
"wave_latest": "2026-05-18T23:00:00+00:00",
"rain_source": "openmeteo-forecast",
"rain_status": "ok",
"tide_source": "noaa-tides-9411340",
"satellite_source": "erddap-multi",
"satellite_status": "ok",
"satellite_latest": "2026-05-13T12:00:00+00:00",
"streamflow_sources": [],
"ingest_run_at": "2026-05-15T17:07:43Z"
}