Harb. & Nav. Code, § 773.5

The operator of a charter boat, or the operator’s employee or agent, shall require each passenger to don a life preserver under any of the following conditions:

(a) When conditions of rough weather or heavy seas pose a threat to the vessel or its passengers.

(b) When there is a casualty to the vessel including, but not limited to, any of the following:

(1) Loss of watertight integrity.

(2) Loss of propulsion or steering in close proximity to a shoal or shore.

(3) Fire at sea.

(4) When under tow.

(c) When crossing or navigating the bar or shoal at or near the entrance of any California harbor where weather conditions, surface current, breaking seas, or severely reduced visibility, cause an increase in the possibility of a sudden emergency that might prevent passengers from donning life preservers before entering the water.

(d) As used in this section:

(1) “An increase in the possibility” means a decrease in the certainty of a reasonably prudent operator that normal operation of the charter boat would avoid any sudden mishap.

(2) “Normal operation” means operation without resort to emergency procedures or other extraordinary measures to maintain course.