California Code, Government Code - GOV § 831.21

(a) Public beaches shall be deemed to be in a natural condition and unimproved notwithstanding the provision or absence of public safety services such as lifeguards, police or sheriff patrols, medical services, fire protection services, beach cleanup services, or signs. The provisions of this section shall apply only to natural conditions of public property and shall not limit any liability or immunity that may otherwise exist pursuant to this division.

(b) This section shall only be applicable to causes of action based upon acts or omissions occurring on or after January 1, 1988.