Verify the accuracy of survey data including measurements and calculations conducted at survey sites. Search legal records, survey records, and land titles to obtain information about property boundaries in areas to be surveyed. Calculate heights, depths, relative positions, property lines, and other characteristics of terrain. Prepare and maintain sketches, maps, reports, and legal descriptions of surveys to describe, certify, and assume liability for work performed. Direct or conduct surveys to establish legal boundaries for properties, based on legal deeds and titles. Prepare or supervise preparation of all data, charts, plots, maps, records, and documents related to surveys. Write descriptions of property boundary surveys for use in deeds, leases, or other legal documents. Compute geodetic measurements and interpret survey data to determine positions, shapes, and elevations of geomorphic and topographic features. Determine longitudes and latitudes of important features and boundaries in survey areas using theodolites, transits, levels, and satellite-based global positioning systems (GPS). Record the results of surveys including the shape, contour, location, elevation, and dimensions of land or land features. Coordinate findings with the work of engineering and architectural personnel, clients, and others concerned with projects. Establish fixed points for use in making maps, using geodetic and engineering instruments. Train assistants and helpers, and direct their work in such activities as performing surveys or drafting maps. Adjust surveying instruments to maintain their accuracy. Plan and conduct ground surveys designed to establish baselines, elevations, and other geodetic measurements. Analyze survey objectives and specifications to prepare survey proposals or to direct others in survey proposal preparation. Develop criteria for survey methods and procedures. Survey bodies of water to determine navigable channels and to secure data for construction of breakwaters, piers, and other marine structures. Conduct research in surveying and mapping methods using knowledge of techniques of photogrammetric map compilation and electronic data processing.