theviz.

Dive visibility in Cape Town

Cape Peninsula · False Bay · Overberg

What the underwater visibility is forecast to do across Cape Town's dive sites today, tomorrow and the day after — modelled from swell and wind history, with the uncertainty stated rather than hidden.

Dive visibility in Cape Town, tomorrow (Wednesday 19 August 2026): the clearest water is forecast at Buffels Bay with a median of 7.4 m and conditions rated diveable. Across all 18 covered sites the median forecast is 4.3 m, and 5 sites are rated diveable during daylight hours. Figures are modelled estimates over daylight hours, not measurements.

Every Cape Town dive site, ranked by tomorrow's visibility

SiteRegionToday
18 Aug
Tomorrow
19 Aug
Thursday
20 Aug
Conditions
Buffels Bay False Bay, inside Cape Point 8.4 m7.4 m8.3 m Diveable
Partridge Point False Bay, western shore, north of Smitswinkel Bay 7.3 m6.1 m6.6 m Not diveable
Glencairn False Bay, western shore, near Seaforth/Simon's Town 6.7 m6.1 m6.3 m Touch and go
Boulders Beach False Bay, western shore (Simon's Town) 6.5 m5.5 m6.0 m Diveable
Castle Rock False Bay, western shore, near Seaforth/Simon's Town 6.0 m5.1 m5.4 m Touch and go
Roman Rock False Bay, offshore reef near Simon's Town 6.2 m5.0 m5.3 m Not diveable
Millers Point False Bay, western shore 5.7 m5.0 m5.2 m Touch and go
A-Frame False Bay, western shore (Simon's Town, Oatlands Point) 5.6 m4.8 m5.2 m Diveable
Windmill Beach False Bay, western shore (Simon's Town) 5.9 m4.8 m5.2 m Diveable
Long Beach False Bay, Simon's Town 4.9 m4.4 m4.9 m Diveable
Oudekraal Atlantic seaboard, between Bakoven and Llandudno 5.0 m4.0 m4.4 m Not diveable
Pyramid Rock False Bay, western shore, near Miller's Point 4.4 m3.5 m3.6 m Not diveable
Moonlight Beach Overberg coast, Grootbaai, east of Hangklip lighthouse 3.7 m3.2 m3.5 m Not diveable
Rooi Els Overberg coast, east side of False Bay, near Gordon’s Bay 3.3 m3.0 m3.1 m Not diveable
Cape Hangklip Overberg coast, headland east of Pringle Bay 3.5 m2.9 m3.2 m Not diveable
Cosy Bay Atlantic seaboard, Oudekraal, between Bakoven and Llandudno 3.1 m2.7 m3.4 m Touch and go
Bakoven Atlantic seaboard 3.1 m2.6 m2.9 m Not diveable
Clifton Atlantic seaboard 2.5 m2.0 m2.5 m Not diveable

Median modelled visibility in metres, averaged over daylight hours. "Conditions" is the best daylight hour tomorrow, called on the weakest safety gate — entry and exit, bottom surge, current, wind or surface chop.

Forecast generated 2026-08-17 23:28 UTC. Updated three times daily.

Why Cape Town visibility is so hard to guess

Water clarity here is a lagging quantity. It is set by how hard the bottom has been stirred over the preceding days and how long the silt has had to drop out again, which is why an instantaneous swell forecast tells you almost nothing about what you will actually see. theviz reads six days of swell and wind history at each site, runs it through bottom-stirring physics, and lets it settle three days forward.

Cape Town also has two effectively separate oceans. The Atlantic seaboard sites — Clifton, Bakoven, Oudekraal — clean up on a southeaster that wrecks False Bay, while Simon's Town and the False Bay western shore come good on a northwester. That is why the table above regularly has excellent and unworkable sites on the same day, and why a single "Cape Town visibility" number would be meaningless.

What the numbers mean

Every figure is a median drawn from an ensemble: five wave models crossed with three weather models, carried through separately rather than averaged first. The per-site pages give the 10th–90th percentile band and the probability of diveable conditions alongside the median. A wide band means the models disagree, which is information in itself — it is the difference between "probably 8 m" and "anywhere from 3 to 14 m".

Full method, inputs and known limitations: methodology. Hourly detail and the fan chart: live forecast.

Modelled estimate, not an observation.
theviz forecasts water clarity from swell and wind history. It does not measure it, and it is not navigation or dive-safety advice. Conditions change fast; check locally, dive within your training, and verify marine protected-area boundaries before spearfishing.