Dive conditions in Catalina Island

Notable species

Catalina Island is known for:

Typical water visibility

Summer visibility around Catalina Island is commonly reported in the 20 to 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.

The app shows a model estimate of today's visibility here, with a confidence figure.

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.

Table baked Oct 15, 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.

Ceiling artifact global-reef-v10-obis-world; table baked Oct 15, 2026.

What Submarius shows for Catalina Island

This page reads Catalina Island at 33.39°N, 118.42°W, in Southern California. Open the same point in the app for:

• A 0 to 10 rating. For diving at Catalina Island today, from Rough to Prime, and you can tap any factor to see why.
• Best 3 hour window. The three hours in the next 24 that score best.
• Tide. Rising, falling or slack, the next high or low, and a 24 hour curve.
• Wind. Speed and direction, with gusts.
• Waves and swell. Wave height and swell, with the second and third swell by the hour.
• Water temperature. With the air temperature underneath.
• Current. Drift in knots and the next slack, from a regional model, so it's offshore drift, not your entry.
• Visibility estimate. A model estimate with a confidence figure, not a measurement.
• Weather warnings. National Weather Service warnings for this spot and its marine zone.
• 8 day forecast (Pro). Days 2 to 8, hour by hour.

Reefs and wrecks near Catalina Island

The reefs and wrecks layer in the app marks charted wrecks, reefs and obstructions around Catalina Island, where sources have them. Tap one for the seabed depth beside it (an estimate where no chart reports one), the least depth over the structure where a chart sounding exists, and today's conditions at that spot. The structures are merged from NOAA nautical charts and other public sources, so coverage is densest in US waters. It's a Pro map layer.

Safety in the water

Every safety tool in Submarius is free. With Safety Watch you set a "back by" time and pick who watches. If you don't check in by then, the server alerts them by push or email, even if your phone is dead. It needs a free account and never contacts the coast guard.

When Spearfishing is your mode, a shark awareness card also lists the shark species recorded in the area and any community sightings from the last 48 hours.