hmmmm, picture ID and CPL are not linked in any way I can find. If you are required to have a CPL to be carrying the firearm in the manner and place you need to have it on your person and to present to LEO upon a valid request.
RCW 9.41.050 http://apps.leg.wa.gov/rcw/default.aspx?cite=9.41.050
RCW 9.91.025 http://apps.leg.wa.gov/rcw/default.aspx?cite=9.91.025 (f) Carries any flammable liquid, explosive, acid, or other article or material likely to cause harm to others, except that nothing herein prevents a person from carrying a cigarette, cigar, or pipe lighter or carrying a firearm or ammunition in a way that is not otherwise prohibited by law
are teh two applicable sections I can dig up quickly. There are some previous posts about the ferries and the buses, but the search function here doesn't like me.