“The course provides instruction in long-range patrolling, amphibious operations, hydrographic surveys, and specialized ground combat tactics.”

“The ship carries two small hydrographic survey launches, equipped with high-frequency sonar to operate in depths of 10 to 260 feet.”

“Of these techniques, the derivation of DEM's from vector hypsographic and hydrographic data produces the most accurate model.”

“The coast survey is to furnish the requisite information of the hydrographical and topographical nature.”

“The regeneration project manager said a hydrographical survey of the area using geophysical scanning would take place next month.”

“Once a lake situated in a soft soil environment reaches a critical surface area, geographical and hydrographical processes will intensify the erosion of the shores.”