A locate device for a locate operation to detect a presence or an absence of one or more underground facilities is configured to access and display facilities map information, and/or other image information, as a visual aid to facilitate the locate operation. In various aspects, methods and apparatus relate to: selection of an appropriate “base” facilities map, or information from a database of facilities map data, relating to a given work site/dig area; selection of an appropriate pan and/or zoom (resolution) for displaying facilities map information; appropriately updating displayed facilities map information while a locate device is used during a locate operation (e.g. changing pan, zoom and/or orientation); overlaying on the displayed facilities map information locate information and/or landmark information relating to the locate operation; and storing locally on the locate device, and/or transmitting from the locate device, facilities map information and/or overlaid locate/landmark information (e.g., for further processing, analysis and/or subsequent display). In one aspect, a location at which an indication of detection of a facility is generated is compared to a location of a facility line as indicated by the facilities map information/image information, and an alert is generated based on the comparison.