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In-House Hydrographic Surveyors

Does your project require a hydrographic survey? At S.T. Hudson, our hydrographic surveyors use the most sophisticated sonar and inertial GPS available in the industry.

Our Hydrographic Surveying Capabilities

Our in-house survey crews use the latest equipment and technology to perform high resolution hydrographic surveys. We utilize a variety of tools and skills to produce the detailed data you need to make informed decisions.

Our ability to verify data from scanning sonar or multibeam surveys with diver verification is a key tool in the in-house capabilities of S. T. Hudson. In addition, our hydrographic surveyors use real-time kinematic (RTK) positioning to broadcast to survey vessels, achieving centimeter-level vertical and horizontal accuracies. When remote geographic locations make this impossible, we use software to post-process the data to the same tolerances as RTK.

Our certified hydrographers and engineers consult on a variety of dredging related issues, including preparation of specifications, pre- and post-dredging surveys, monitoring of siltation rates, volume calculations for payment quantities, and assistance in obtaining required local, state and federal permits.

Our solid background in underwater construction allows us to deliver cost-effective repairs, prioritize construction, and make reliable estimates so our clients can appropriately allocate and schedule maintenance funding. Our services include:

  • Multibeam Hydrographic Surveys - Good for collecting depths in mid- to deep-water columns, multibeam hydrographic surveys can serve two purposes: berth clearance and condition surveys.
  • Dual-Frequency Single Beam Surveys - We use dual-frequency single beam surveys to determine water depth by measuring the travel time of a short sonar pulse, or “ping”. Hydrographic survey-grade single beam echo sounders are able to provide accurate bottom depths by distinguishing the real bottom from false readings caused by fish, debris, aquatic vegetation and suspended sediment.
  • Scanning Sonars - This tool is used for object detection, sending out a sound wave that reflects off objects and can be used regardless of water visibility.
  • Side Scan Sonars - Used for object detection, side scan sonar measures the strength of returning echoes to create an image of the sea floor.
  • Sub-Bottom Profiling - Using principles of seismic reflection, sub-bottom profiling can identify and characterize layers of sediment or rock under the sea floor.
  • ROV Operations - We utilize remotely operated vehicles (ROVs) to investigate areas where divers cannot operate safely.
  • Magnetometer - This instrument, used for measuring the magnitude and direction of a magnetic field, can detect magnetic anomalies beneath the surface.

ST Hudson has been distinguished by their responsiveness, timely performance, thoroughness and cost-effective solutions to different design problems.

Motiva Enterprises LLC -

Explore Our Surveying Work

Energy Transfer Marcus Hook Industrial Complex

Energy Transfer Marcus Hook Industrial Complex

Dock 1A, 2A, and Fire Water Pump EPC Contracts
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Energy Transfer Marcus Hook Industrial Complex

Energy Transfer Marcus Hook Industrial Complex

Addition of a New Fire Water Intake System
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Energy Transfer Marcus Hook Industrial Complex

Energy Transfer Marcus Hook Industrial Complex

Dock 2A Upgrades / Modifications
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Pro Tips

Most dock facilities, both public and private, have requirements for periodic dive inspections to check the underwater condition of your berth structures. The frequency of these inspections can be dictated by the owner of the facility or federal, state, or municipal agencies. In the absence of these requirements, it is advisable to perform dive inspections using certified hard-hat divers once every 1-3 years.

Single-beam hydrographic surveys are good for shallow to mid-water depths. Multibeam hydrographic surveys are good for mid to deep-water depths. A multibeam hydrographic survey can serve two purposes: berth clearance and condition surveys.

Single beam surveys are adequate for your required periodic dredge depth soundings. However, for a more complete picture of the topography of the floor of your berthing area, consider using a multibeam survey.

Most dock facilities, both public and private, have requirements for periodic hydrographic surveys. The frequency of these scans can be dictated by the owner of the facility or federal, state, or municipal agencies. In the absence of these requirements, it is advisable to check the depth of your dock using single or multibeam scanning sonar once every 1-3 years depending on the silting conditions at your site.

Most dock facilities, both public and private, have requirements for periodic underwater scans to check for obstructions. The frequency of these scans can be dictated by the owner of the facility or federal, state, or municipal agencies. In the absence of these requirements, it is advisable to check the depth of your dock using scanning sonar once every 1-3 years.

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