Isthmus
Conditions & tides
Scored by DiveConnect's site-physics model
Marine forecast via Copernicus Marine. Score is a rule-based guide from swell/wind vs. the site's exposure — always dive your own assessment.
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About this site
Isthmus, also called Isthmus Reef, is a rocky reef dive at Santa Catalina Island in California. Depths run between 15 and 110 feet plus (about 4.6 to 33.5 metres), and the site has both shallow and deep areas.
The reef has steep walls with plenty of ledges on its west, north and east sides, while the south side and the top are shallow. Rocky structure with crevices and healthy kelp holds kelp bass, rockfish, sheepshead and lobsters, and sea lions and harbor seals are also seen here.
Marine life here
Confirmed by our research team, reported by independent divers, or observed nearby via iNaturalist — each entry is labelled with its source.
Kelp BassParalabrax clathratusReported here · unconfirmed
Blacksmith ChromisChromis punctipinnisReported here · unconfirmed
California SheepheadBodianus pulcherReported here · unconfirmed
GaribaldiHypsypops rubicundusReported here · unconfirmed
Rock WrasseHalichoeres semicinctusReported here · unconfirmed
Crowned sea urchinCentrostephanus coronatusReported here · unconfirmed
Durable tips from divers — access, hazards, marine life, facilities. For day-of conditions, use the report tool in the conditions card above.
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