Most buyers and sellers of real property assume that the property lines are where they seem to be, along the driveway, the fence, the hedge or other obvious lines. Often, this is true. But, a surprising amount of time, the property line does not coincide with fences and other markers.
The only way to be sure where the lines are is to hire a surveyor. You should hire a surveyor, if you are involved in a dispute with a neighbor over a fence, a wall or another issue, which depends upon knowing where the lines are. It is also prudent to hire a surveyor, if you are planning to build a wall, put in a driveway or otherwise do expensive work near the property line.
Surveyors are professionals who are licensed and regulated by the State of California. The laws regulating surveyors are set forth in the Professional Land Surveyors Act, California Business & Professions Code Section 8700-8805. It is unlawful for unlicensed people to practice land surveying. B&P Code Section 8725.