Wash. Rev. Code § 80.36.070
Any person who injures or destroys, through want of proper care, any necessary or useful fixtures of any telecommunications company, is liable to the company for all damages sustained thereby. Any vessel which, by dragging its anchor or otherwise, breaks, injures or destroys the subaqueous cable of a telecommunications company, subjects its owners to the damages hereinbefore specified.
No telecommunications company can recover damages for the breaking or injury of any subaqueous telecommunications cable, unless such company has previously erected on either bank of the waters under which the cable is placed, a monument indicating the place where the cable lies, and publishes for one month, in some newspaper most likely to give notice to navigators, a notice giving a description and the purpose of the monuments, and the general course, landings and termini of the cable.
RCW 80.36.070