Seabright (Castle) State Beach

A long sandy beach between the Boardwalk and the Santa Cruz Harbor. Fire rings are available and dogs are permitted on leash.

Get directions to this beach

Water Quality

Passed water quality tests 60-95% of the time
Historical Status
This status is based on the latest sample, taken on May 3th, 2023. Swim Guide - Main updates the status of this beach as soon as test results become available. These results were posted to Swim Guide on May 9th, 2023 at 9:00 AM.

For water quality icon legend, click:

Current Weather

14°C

Cloudy with a few clear breaks

Report Pollution

Monitoring Frequency

Source Information

Santa Cruz County’s department of Environmental Health Services provides recreational water quality to the public through their website and by calling 831-454-3188. Samples are collected and tested for the levels of 3 types of bacteria. Please refer to the monitoring frequency in the beach description as frequencies vary throughout the year. Swim Guide checks daily for the latest results.

Country standards for indicator bacteria are as follows:
Total Coliform > 10,000 MPN (Most Probable Number) / 100 ml of water
E.coli > 400 MPN / 100 ml
Enterocococcus > 104 MPN / 100 ml

A beach will be marked Green when all three levels of bacteria are below standards

A beach will be marked Red when 1 of the bacteria levels are above the standard

A beach will be marked Grey when there is no current or reliable information.

The county advises that you avoid swimming in areas at risk to storm water runoff for at least 3 days after heavy rain.

Water Quality Graph

Other Beaches Near This One

Beach	Location	Water Quality
Main Beach @ Boardwalk Santa Cruz, California	Santa Cruz, California	Historical Status
Main Beach @ San Lorenzo River Santa Cruz, California	Santa Cruz, California	Historical Status
Twin Lakes State Beach Santa Cruz, California	Santa Cruz, California	Historical Status
San Lorenzo River @ Trestle Santa Cruz, California	Santa Cruz, California	Historical Status

	Green means the beach’s most recent test results met relevant water quality standards.

	Red means the beach’s most recent test results failed to meet water quality standards.

	Grey means water quality information for the beach is too old (more than 7 days old) to be considered current, or that info is unavailable, or unreliable.

	Green means the beach passed water quality tests 95% of the time or more.

	Yellow means the beach passed water quality tests 60-95% of the time.

	Red means the beach failed water quality tests 40% of the time or more.

	This means that this site has been issued a Blue Flag status for the current swimming season. This status does not indicate current water quality.

	Red means the water at the site has water quality issues or there is an emergency.

	Grey means there is no current water quality information, the beach is under construction, there has been an event that has rendered water quality information unreliable or unavailable.