Cal. Harb. & Nav. Code § 4005

If the owner of the land is a nonresident of the county, the sheriff may make service by leaving a copy of the notice of application with the occupant, or agent of the owner. If there is no occupant, or agent of the owner, the sheriff may place a copy in the post office addressed to the owner 30 days prior to the day set for the hearing. If the owner is a minor, has a mental health disorder, lacks mental capacity, or is a decedent, notice shall be served on the owner’s guardian, administrator, or other legal representative.