NOAA’s Office of Coast Survey provides navigational services intended to ensure the safe and efficient passage of maritime commerce through oceans and coastal waters within U.S. jurisdiction, and in the Great Lakes. In this capacity, the Office of Coast Survey develops, updates, and maintains more than 1,000 nautical charts—maps used for navigating waterways—containing information about water depth, the shape of the water body floor and coastline, the location of possible obstructions, and other physical features within these water bodies. According to NOAA documentation, nautical charts provide information critical to safe navigation, such as symbols that inform ship captains or recreational boaters if an area is shallow or has dangerous conditions that could imperil navigation. Hydrography is the science that informs the surveying methods for collecting the data used to create and update nautical charts. In addition, information collected through hydrographic surveying supports a variety of maritime functions such as port and harbor maintenance, beach erosion and replenishment studies, management of coastal areas, and offshore resource development. NOAA operates four ships that predominantly support hydrographic surveys: the Fairweather, Ferdinand R. Hassler, Rainier, and Thomas Jefferson (see fig.1). The Hassler, commissioned in 2012, is the newest of the four vessels. NOAA also procures and oversees hydrographic surveying and related services from the private sector. NOAA officials said the congressional committee reports accompanying NOAA’s appropriations acts for fiscal years 2007 through 2016 provided about $342 million of the agency’s appropriation for the Hydrographic Survey Priorities/Contracts budget line item. The most recent contracts were awarded in June 2014 to eight hydrographic survey companies for a 5-year period and are valued at up to $250 million over this contract period based on NOAA documents. In addition, according to NOAA officials, NOAA works with other federal agencies to collect hydrographic survey data. For example, the U.S. Army Corps of Engineers provides such data for the federal harbor waterways that support the U.S. port system. NOAA primarily uses two kinds of sonar for hydrographic surveying— multibeam and side scan. Multibeam sonar measures the depth of the water by analyzing the time it takes sound waves to travel from a vessel to the bottom of the water body and back and provides detailed information about the water body floor. Multibeam sonar is generally used in areas such as the northeast United States and Alaska, where the water body floor is complex and often strewn with rocks. See figure 2 for an illustration of a NOAA ship using multibeam sonar. In contrast, in relatively shallow flat areas like those along the mid-Atlantic coast, NOAA uses side scan sonar. Side scan sonar creates an image of the water body floor but does not determine depths. If NOAA finds a shipwreck or obstruction using side scan sonar, it will determine its depth using multibeam sonar. See figure 3 for an illustration of a NOAA ship using side scan sonar. NOAA’s National Ocean Service is responsible for providing data, tools, and services that support mapping, charting, and maritime transportation activities, among other things. Within the National Ocean Service, the Office of Coast Survey directs the agency’s hydrographic surveying operations. In particular, it develops survey specifications, evaluates new technologies, and implements procedures for acquiring hydrographic survey data, processing the data, and producing nautical charts. Within the Office of Coast Survey, the Hydrographic Surveys Division is responsible for planning, managing, and supporting hydrographic surveying operations. This includes compiling, verifying, and certifying hydrographic data, as well as determining hydrographic survey priorities and issuing an annual hydrographic survey prioritization report. The Hydrographic Surveys Division coordinates with NOAA’s Office of Marine and Aviation Operations to plan and schedule NOAA vessels for hydrographic surveying. The Office of Marine and Aviation Operations manages, operates, and maintains NOAA’s fleet of 16 ships, including the 4 ships that predominantly support hydrographic surveying. According to NOAA officials, during fiscal years 2007 through 2016, NOAA expended about $303 million for its in-house hydrographic survey program. The Hydrographic Surveys Division also works with the Hydrographic Services Review Panel, an external committee that advises NOAA on matters related to hydrographic services, including surveying. The review panel, which was required by the Hydrographic Services Improvement Act Amendments of 2002, is composed of 15 voting members appointed by the NOAA Administrator as well as several NOAA employees who are nonvoting members. Voting members must be especially qualified in one or more disciplines relating to hydrographic data and services, vessel pilotage, port administration, coastal management, fisheries management, marine transportation, and other disciplines as determined appropriate by the NOAA Administrator. The NOAA Administrator is required to solicit nominations for panel membership at least once a year; voting members serve a 4-year term, and may be appointed to one additional term. The Director of the Office of Coast Survey serves as the designated federal officer. NOAA’s standards for hydrographic surveying are contained in a technical specifications document known as the Hydrographic Surveys Specifications and Deliverables. The document is updated annually by NOAA hydrographers and, according to NOAA officials, is also the standard on which many other hydrographic survey entities base their hydrographic surveying requirements. In addition, NOAA maintains a quality assurance program for all hydrographic survey data submitted by the private sector and NOAA hydrographers. The quality assurance program includes three main review procedures intended to ensure that hydrographic data submitted to NOAA meet quality standards: the Rapid Survey Assessment, Survey Acceptance Review, and Final Survey Review. See appendix I for additional information about NOAA’s data quality standards and review process. NOAA uses a three-step process to determine its hydrographic survey priorities. In addition, in an effort to improve its priority setting, NOAA is developing a model to better assess hydrographic risks to ships. According to NOAA’s standard operating procedure and NOAA officials, NOAA uses a three-step process to determine its hydrographic survey priorities. Under this process, NOAA (1) identifies the areas in greatest need of surveying, (2) evaluates resources, including funding and vessel availability, and (3) develops an annual hydrographic surveying plan, which identifies the resulting hydrographic survey priorities. The plan specifies the locations, vessels, and schedules for NOAA hydrographic survey projects and the locations and time frames for private sector hydrographic survey projects. (See fig. 4.) NOAA first identifies the areas the agency considers to be in the greatest need of a hydrographic survey, using an approach it developed in 1994 called NOAA Hydrographic Survey Priorities, according to NOAA’s standard operating procedure and NOAA officials. NOAA identifies areas of “navigational significance” based on depth, draft of ships, and potential for dangers to marine navigation. NOAA then determines which of these navigationally significant areas are in greatest need of surveying by considering (1) shipping tonnage and trends, (2) age and quality of surveys in the area, (3) seafloor depth, (4) potential for unknown dangers to navigation due to environmental or human influences, and (5) requests for surveys from stakeholders such as pilot associations and the U.S. Coast Guard, and requests received through NOAA’s regional navigation managers. Through this process, NOAA designates high-priority areas in any of four categories: Critical areas. Areas that NOAA identified in 1994 as experiencing such circumstances as high shipping traffic or hazardous material transport or having a significant number of survey requests from users. Emerging critical areas. Areas in the Gulf of Mexico and Alaska that NOAA identified after 1994 that met the critical area definition but that NOAA chose to designate in a separate category from the 1994 critical areas for tracking purposes. Resurvey areas. Areas that NOAA identified as requiring recurring surveys because of changes to seafloors, use by vessel traffic, or other reasons. Priority 1-5 areas. Areas that do not fall into any of the three categories above are subdivided into five priority areas based on the date of the most recent survey and the level of usage by vessels. Until 2012, according to NOAA’s standard operating procedure, NOAA used the results of its approach for identifying areas most in need of surveying to publish annual hydrographic survey prioritization reports—a component of the overall hydrographic surveying plan. However, NOAA officials said they found this approach increasingly outdated because it did not reflect changing ocean and shipping conditions or take advantage of available technology. These officials said they are in the process of developing a new methodology (described later in this report) to help identify areas that need surveys. According to NOAA officials, they have continued to update computerized mapping files and reports related to hydrographic survey priorities since 2012 but have not published new hydrographic survey prioritization reports. However, these officials said they will provide information to the public upon request. According to NOAA’s standard operating procedure and NOAA officials, once NOAA identifies its highest priority areas, the agency compares its priorities to those identified by external stakeholders through NOAA’s navigation managers and its Integrated Ocean and Coastal Mapping program. NOAA officials said this input helps them understand potential economic and safety issues, among other things, that may affect hydrographic survey priorities.