Hydrography is the science of measuring and describing the physical features of the navigable portion of the Earth's surface and adjacent coastal areas. Hydrographic surveyors survey these bodies of water to see what the "bottom" looks like. This is a highly complex task; due in part to natural fluctuations in fish populations, and the influence of phenomena such as the El Niño-Southern Oscillation (ENSO) and global change cannot be ignored. These phenomena are the subject of intense research all over the world. As a result, fish abundances fluctuate significantly over time, affecting regulatory estimates. The second problem is the lack of knowledge to properly understand and correlate resource behavior with environmental variability. The above leads to the need for long-term environmental research to provide fisheries management decision-makers with the most pertinent information for promulgating appropriate conservation measures. Flumes also play an important role in this task, contributing various long-term data that enable the feed prediction models used by institutions. However, these users demand quality products that are very practical for the various purposes mentioned above. Hydrographers generally use the advanced and complex techniques required. You should be able to meet these requirements. Hydrography is the science that measures and describes the physical properties of bodies of water and the land areas adjacent to those bodies of water. Multibeam surveying is the primary method for obtaining hydrographic data. By mapping the depth of water, the shape of the seafloor and coastline, the location of potential obstacles, and the physical features of water bodies, hydrography helps maritime transportation systems navigate safely and efficiently. A multi-beam sonar beam sweeps across the seafloor as the vessel passes through the survey area. The fan beam bounces off the seafloor and back to the ship where the depth is recorded. These direct and indirect benefits are traditionally not perceived as economic value to coastal states because they are difficult to quantify. Also, their actual value varies somewhat depending on the specific economic, recreational, and defense activities of each coastal state. Convincing governments to invest in hydrographic and bathymetric surveys can be difficult. However, even in the absence of quantitative analysis, there are strong theoretical and qualitative arguments that recognize the significant value of hydrographic services as an integral part of national infrastructure and as an important prerequisite for other maritime activities. Therefore, providing government information detailing the secondary and tertiary benefits of bathymetric surveys and hydrographic services can further influence investment in these essential conditions for economic growth. CDRE Nairn is an Australian Hydrographer and Chief of the Navy's Department of Hydrographic, Meteorological and Oceanography. His naval career includes command of four seas and appointment as commander of the world's first laser airborne echo sounder. He has a degree in Strategic Studies, Surveying and Management and is a graduate of the Australian Business Board. CDR Connon is currently the Expeditionary Warfare Program Manager for the Naval Meteorological and Oceanographic Command and he serves as Vice Chair of the IHO's Capacity Building Subcommittee. Perhaps equally important is the need for hydrographic and bathymetric features to assist in the formulation of national and local strategies for conserving and protecting marine resources.