Hydrographic Surveying

Using a variety of sonar systems, hydrographic surveying quantifies and qualifies the seabed. Hydrographic surveying takes place in rivers, lakes, waterways, constricted water bodies and beaches. It occurs both inshore and offshore. And it ranges from the intertidal zone to the deep ocean floor. Hydrographic surveys are essential to keeping our coastal resources healthy, viable and safe.

Hydrographic surveyors provide the surveying and mapping tools necessary to monitor coastline erosion, measure and map navigable water bodies, monitor shorelines and beaches, provide data for hurricane recovery programs, measure depths and compute volumes for dredging projects, locate and map submerged obstructions, and prepare for underwater construction.

McKim & Creed’s extensive resources include trailerable survey vessels ranging from 10 to 27 feet, a remotely operated survey vessel (6-ft Z-boat) and support vessels. Our team includes ACSM certified hydrographers, USCG boat captains and hydrographic technicians. These highly skilled professionals utilize our technical resources to efficiently, accurately and safely respond to all your hydrographic surveying needs. Surveys performed by our team include single beam sonar, multibeam sonar, side scan sonar, magnetometer, sub-bottom profiling, bottom grabs and the use of z-boats.

Hydrographic Specialties

Single Beam Sonar

Single beam acoustic depth sounding is a widely used depth measurement technique.

McKim & Creed utilizes dual-frequency single beam echosounders that operate at both high and low frequencies. This allows the dual-frequency transducer to be used in areas of high silt deposition (fluff layer), whereas conventional single, high-frequency units only record the top of the silt level. Additionally, single beam data can be processed quickly when compared to multibeam data.

Single beam sonar is recommended for beach nourishment jobs, in areas where depths are shallower than 12 feet, and whenever full bottom coverage is not required.

Multibeam Sonar

Acoustic multibeam survey systems are typically used in areas where the bottom is deeper than 12 feet and when full bottom coverage is required.

Multibeam systems can be used for project condition surveys, dredging measurements, channel clearance and construction payment surveys. The system can also be configured to cover over 180-degree swaths. This allows side-looking, full-coverage underwater topographic mapping of constricted channels, lock chambers, dams and other underwater control structures.

Side Scan Sonar

Side scan sonar is a high-resolution imaging tool that provides a general depictive map on both sides of a survey vessel’s path. This survey method provides the relative height of objects off the surrounding sea floor, from which an approximate top elevation may be roughly estimated.

This type of survey can be combined with multibeam to provide actual depth sounding of structures observed in the side scan images.

Magnetometer

A magnetometer measures the variation in the earth’s magnetic field and can detect anthropogenic features on the seabed. It can recognize objects that cannot be identified using side scan sonar and multibeam sonar.

Magnetometer surveys are used in a variety of fields and are particularly well suited to detecting and mapping ferrous objects such as anchors, cables, pipelines, lost dredging equipment, shipwreck debris, munitions, aircraft and engines.

Sub-bottom Profiling

A sub-bottom profiling system uses low-frequency sound energy to identify and characterize layers of sediment or rock under the seafloor.

This technology can be used in bridge/shoreline scour surveys, buried object location, geohazard surveys, geological studies and mining/dredging surveys.

Projects