Viz below normal at 40 ft, light wind, slack tide.
Catalina Cam observation: visibility 25–40 ft (auto, medium confidence). No highlights/replay badge, frames show live blue water with no dock pilings in view. Nearby reef rock at lower left is reasonably crisp, and small blacksmith-sized fish (~8 in) appear as small but recognizable dark shapes mid-frame, implying roughly 25-35 ft; the sand/cobble bottom at lower right fades into haze at a similar range, and the far water column is featureless blue haze with a visible light-scatter cast. Nothing distinct remains beyond that, so I put visibility in the 25-40 ft band, a bit under the October average.
Dive area in Cat Harbor SMCA. Eelgrass, tidal flats, rocky shoreline, sandy seafloor at Catalina; garibaldi, California sheephead, kelp bass, leopard sharks. Diving and snorkeling in harbor; ferry to Two Harbors then a half-mile walk. Take rule: Lobster, urchin, squid, finfish by hook-line or spear. (Source: CA Dept. of Fish & Wildlife.)