California Code, Harbors and Navigation Code - HNC § 448

The vessel traffic service shall be advisory in nature.  Nothing in this article relieves, or is intended to relieve, any vessel, its owners, agents, charterers, operators, or other responsible or designated parties of command of the vessel or of any responsibilities they would otherwise have respecting the navigation and operation of any vessel.  Each vessel within the VTS area shall be responsible for its safe navigation in accordance with the International Regulations for Preventing Collisions at Sea (1972) and any other international and local rules and regulations.