Scuba Diving · Southern California

Scuba Diving in Catalina Island

One of the most popular spearfishing and diving islands on the US West Coast. Kelp forests on the front side, bluewater pelagic shots on the back side. Short ferry from LA/OC.

Live conditions, water-clarity forecast, and water temperature for scuba diving in Santa Catalina Island, CA. Open the app for a live verdict and a tappable factor breakdown, free, no signup. Pro extends the forecast to 8 days.

Open live conditions →

Conditions snapshot: Oct 5, 2026

Visibility

36 ft

20–65 ft range

Water

73°F

Wind

7 kts

Wave

2.2 ft

Swell

1.7 ft

Period

11.9s

Snapshot from Oct 5, 2026. Live values, factor breakdowns, and 8-day forecast in the app.

Notable species

Catalina Island is known for:

YellowtailWhite SeabassCalico BassSheepheadBlack Seabass

Typical water visibility

Summer visibility around Catalina Island is commonly reported in the 20–50 ft range, a community-guidance estimate, not a measurement. Rain, river discharge, swell mixing, and seasonality can shift real conditions dramatically day to day.

That's exactly why Submarius exists. The in-app clarity forecast starts from this coast's typical clarity for the time of year, built from in water measurements and satellite ocean color, then subtracts wave stirring, river and runoff plumes, and tide movement to estimate how far you'll actually see, shown as a low to high range, not a seasonal average.

How the clarity forecast works →

Last 7 days of model reads

One model estimate recorded each morning (UTC) for Catalina Island. These are model estimates, not measurements; the low and high columns are the p10 to p90 range around the middle estimate.

Day	Low ft	Estimate ft	High ft
Oct 5	20	36	66
Oct 4	20	36	66
Oct 3	20	35	65
Oct 2	20	36	66
Oct 1	20	36	65
Sep 30	22	33	48
Sep 29	13	27	48

Table baked Oct 5, 2026; days the recorder missed are simply absent.

Clearest months at Catalina Island

Model climatology from the baked clarity ceiling: the typical day and the best case (90th percentile) visibility for each month, with a seasonal algae bloom proneness flag. These are labelled model estimates, not measurements.

Month	Typical ft	Best case ft	Bloom risk
Jan	49	62	low
Feb	28	49	low
Mar	28	32	low
Apr	23	38	low
May	23	36	low
Jun	23	38	low
Jul	25	39	low
Aug	27	49	low
Sep	33	49	low
Oct	36	66	low
Nov	39	66	low
Dec	39	66	low

Ceiling artifact global-reef-v10-obis-world; table baked Oct 5, 2026.

What Submarius shows for Catalina Island

Verdict score (0–10). Aggregates wind, swell, tide, moon, and water clarity into one decisive number.
Best window. The 2–3 hour stretch each day when conditions peak.
8-day forecast. Auto-scaled line graph showing which day this week is trending good.
Water clarity forecast. Secchi-depth estimate with uncertainty bounds and the next best vis window.
Free, anonymous. Check conditions with location on, no signup until you want to save spots or post reports.

Safety in the water

Submarius ships OCEARCH tagged-shark alerts, community shark sightings, SOS, and buddy GPS sharing, permanently free, regardless of subscription tier. For Catalina Island specifically, the app shows any recent tagged sharks within range and lets you enable push notifications for sightings on your active tiles.