(a) The use of a distinctive blue light as prescribed by the department is reserved for law enforcement vessels and may be displayed during the day or night whenever the vessel may be engaged in direct law enforcement activities, including, but not limited to, those activities specified in subdivision (a) of Section 663.7, where identification of a law enforcement vessel is desirable or where necessary for safety reasons.
(b) That light when used shall be in addition to prescribed lights and day signals required by law.
(c) The display of such blue lights on vessels for other purposes is prohibited.
(d) Any vessel approaching, overtaking, being approached, or being overtaken by a moving law enforcement vessel operating with a siren or an illuminated blue light, or any vessel approaching a stationary law enforcement vessel displaying an illuminated blue light, shall immediately slow to a speed sufficient to maintain steerage only, shall alter its course, within its ability, so as not to inhibit or interfere with the operation of the law enforcement vessel, and shall proceed, unless otherwise directed by the operator of the law enforcement vessel, at the reduced speed until beyond the area of operation of the law enforcement vessel.
(e) The operator of every cable ferry shall take whatever reasonable action is necessary to provide a clear course for any law enforcement vessel operating with a siren or an illuminated blue light, or both.