Land Surveyor in Training (LSIT) Practice Exam 2026 – Your All-in-One Guide to Exam Mastery!

Datums in land surveying establish the reference framework for where things are located and how high they are. There are horizontal datums, which anchor locations in a plane for plan coordinates, and vertical datums, which anchor elevations relative to a reference surface like mean sea level. Since a survey needs both position and height, both horizontal and vertical datums are used. The idea of a “complete” datum isn’t a standard category, so it isn’t applicable. In practice, you’ll see specific horizontal datums (like NAD83) paired with vertical datums (like NAVD88) to provide a full 3D reference.