“Local safety member” also includes any harbor or port police officer, employed by a contracting agency, who is a peace officer as defined in subdivision (b) of Section, 830.33 of the Penal Code and whose principal duties consist of active law enforcement of the laws contained in Chapter 5 (commencing with Section 650) of Division 3 of the Harbors and Navigation Code, the rules and regulations of the California Department of Boating and Waterways, and Chapter 2 (commencing with Section 9850) of Division 3.5 of the Vehicle Code.

This section shall not apply to any contracting agency nor to the employees of a contracting agency until the agency elects to be subject to this section by amendment to its contract with the board, pursuant to Section 20474, or by express provision within its contract with the board.