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Kylie Stewart sets new course for Hydro Data, Inc.


Since joining Hydro Data, Inc. Kylie Stewart has taken leadership rolls in both administration and operations. Her extensive knowledge of business and the natural sciences has helped Hydro Data expand services and keep pace with rapidly changing technology. Welcome Kylie!


Hydrographic Surveys

2010 Hydro Data performed single beam hydrographic surveys to monitor removal of contaminated sediment around  Pier 1 located at the Naval Submarine Base – New London, Groton, Connecticut.  This work was performed for TetraTech EC, Inc. of Langhome, PA under the direction of the Environmental Protection Agency and the U.S. Navy.

Underwater Noise Surveys

2010 Hydro Data, Inc. performed hydroacoustic monitoring of noise produced by pile driving activities associated with construction of a temporary trestle spanning the Housatonic River between Milford and Stratford, Connecticut. This work was performed for O&G Industries of Torrington, Connecticut.

Hydrographic and Side Scan Sonar Surveys

2010 Hydro Data performed single beam, multi-beam sweep surveys and side scan sonar surveys in support of the Amtrak Bridge Replacement Project in Niantic, Connecticut. Pre-construction baseline surveys have been performed and post-construction clearance surveys are under contract. This work is being performed for Cianbro / Middlesex a Joint Venture.

Hydrographic Surveys

2010 Hydro Data, Inc. performed pre-remedial dual-frequency hydrographic surveys to accurately measure and record the lake bottom depths in Lake Cochituate, at the U.S. Army Natick Soldier Systems Center (NSSC) in Natick, Massachusetts. The water depth data was used by the dredge operator for guiding the depth of the cutter head for the removal of a 6” layer of sediment contaminated with PCBs. On completion of the dredging Hydro Data performed a post-dredge survey to ensure the contaminated sediment layer was removed. This work was performed for Innerspace Services of South Casco, ME and for Charter Environmental.

Hydrographic Surveys

Hydro Data, Inc. performed pre- and post-dredge surveys and general condition hydrographic surveys in support of various projects during 2010. These projects included but are not limited to: Vermont Yankee Power Plant, Connecticut River; National Gypsum mooring facilities in Albany, NY and Portsmouth, NH; beach replenishment surveys in Niantic Bay, Long Island Sound; Atlantic Ocean off Moriches, NY; Sprague Energy Plants in Massachusetts; Shennecossett Y.C. in Groton, Connecticut; Saybrook Point Marina, on the Connecticut River; Tern Harbor in Weymouth, MA; Breakwater Key on the Housatonic River; bridge condition surveys in New Haven Harbor, Bridgeport Harbor and the Housatonic River in Connecticut; Goodsell Point Marina in Branford, Connecticut; Harbour Park in Middletown, Connecticut; Staab property in Old Lyme on the Connecticut River; Point-O-Woods Marina, East Lyme, Long Island Sound; Wilde Lake in MD; Wickford Cove, Rhode Island; Pine Orchard, Branford, Long Island Sound; and Chester Marina, on the Connecticut River.

Hydrographic and Side Scan Sonar Surveys

2010 Hydro Data performed pre- and post demolition surveys in support of the Congress Street Bridge Project in Bridgeport, Connecticut. The surveys consisted of complete bottom coverage hydrographic surveys and side scan sonar surveys to insure the federal navigation channel was clear of demolition debris.

Volumetric Computations

-2010 Hydro Data performs volume computations for dredge material removed using data collected on our in-house pre/post dredge surveys. In addition, we perform volume computations for engineering firms and a sister hydrographic survey company located in California. Our latest project was computing dredge volumes removed from the San Francisco Yacht Club for Sea Surveyor, Inc. of CA.

Water Velocity Measurements

2009 Hydro Data performed current profiling surveys around 25 bridges in the State of Rhode Island to support the RI DOT Bridge Scour Program. Both mechanical and acoustic Doppler current profilers (ADCP) were used to collect data that was used by the client for math modeling computations. The work was performed while under contract to SMC of Braintree, MA.

Geophysical Surveys

March 2009 Hydro Data performed water depth and geophysical surveys in St Kitts, St Vincent and Grenada for Sub Vzla of Venezuela to map a proposed pipeline route for offloading product from ships moored at offshore sites. Four routes were surveyed using depth sounders, side scan sonar and a sub-bottom profiler.

Geophysical Surveys

October 2008 Hydro Data, Inc. performed hydrographic and geophysical surveys of the seafloor east of the Virgin Gorda Airport located in Spanish Town, Virgin Gorda, British Virgin Islands in support of the airport expansion project. Final products included water depth charts and seafloor sediment classification maps. 


Two members of Hydro Data's staff are certified as Inshore Hydrographers by American Congress on Surveying and Mapping (ACSM). These staff members each have over 35 years hydrographic survey experience involving hydrography, sediment profiling, navigation services, water quality, current studies, bottom sampling, magnetometer surveys, dye studies, side scan sonar, and the deployment of a variety of underwater instrumentation including  wave, current, temperature, CTD, and tide measuring equipment. All Hydro Data staff members routinely perform hydrographic surveys for dredge permitting, dredge monitoring, dredge spoil disposal monitoring, general site condition investigations, channel clearance inspections, sunken/buried object searches, seafloor classification and bulkhead and/or bridge pier scour inspections. In addition, volumetric computations are routinely performed for dredge payment purposes and for incorporation into bid documents.  Our staff members represent over 75 years of combined hydrographic survey experience representing over 600 projects.




Nancy is certified by the American Congress on Surveying and Mapping (ACSM) as an Inshore Hydrographer (1990). She has 36 years of marine site survey experience in the fields of hydrography, geophysics and oceanography. In 1990 Ms. Byrne established Hydro Data, Inc. with the aim to provide the engineering community with data acquisition and data presentation services. Ms. Byrne is an FAA UAS certified drone pilot.

Nancy's clients include, but are not limited to:


  • U.S. Navy – performed submarine berth clearance surveys and dredge monitoring surveys
  • National Oceanic and Atmospheric Administration (NOAA) – Navigation charting projects (Gulf of Mexico)
  • U.S. Army Corps of Engineers (USACE) – performed surveys for dredge monitoring, unexploded ordinance searches and for regulatory purposes (Northeast United States)
  • U.S. Coast Guard (USCG) – performed surveys for dredge monitoring and for construction debris clearance in navigation channels
  • Department of Transportation (7 States) – Conducted bridge pier Inspection surveys (scour) and performed river discharge studies for bridge pier design.
  • Environmental Protection Agency – performed surveys to support cleanup of PCB’s.
  • Engineering Firms– Collected data for marine structure design, performed pre-construction archeology clearance surveys, conducted water quality studies and computed material volumes for handling and cost estimates.
  • Construction firms – Performed pre/post construction surveys, including sub-bottom obstruction clearance investigations and sea floor classification.
  • Industrial Firms – Surveyed proposed cable/pipeline routes and conducted discharge dispersion studies.
  • Law Firms – Collected data and generated presentations to help resolve disputes.
  • Insurance Companies – Conducted sunken vessel searches for claim investigations.
  • Universities – Collected data to support sediment transport studies.
  • Water Companies – Collected data for reservoir siltation rate studies and computed water volumes.


Other Work

Designed and fabricated an underwater sediment profile camera for a Navy dredge material disposal project.

Designed and wrote the "Vespos" software for all of Hydro Data, Inc.’s hydrographic data collection and data processing.

Developed, marketed, sold and installed custom ship positioning software systems.

Initiated a co-operative project to design and build mini-computers for use on small survey vessels.

Designed and fabricated oceanographic instrumentation deployment structures for long term tide and current studies.

Has been called as an expert witness.

From 1991 to 1998 Nancy was a Member of the ACSM Hydrographer Board and  Co-authored the ACSM hydrographer certification exam. Currently she proctors hydrographer certification exams for ACSM in  the northeast region of the U.S.




Hydro Data, Inc. is certified as a DBE by the Connecticut Department of Transportation in accordance with the U.S. Department of Transportation (see listing www.ct.gov/dot).

Hydro Data, Inc. is a Women-Owned Business Enterprise and a Small Business Enterprise.

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