We bring over a century of combined experience to the table.

The Gravity team of staff and associates are a multi-disciplinary team with extensive marine experience.  We are scientists, engineers, surveyors and merchant marines with niche experience in collecting and analyzing aquatic data.

Ryan McEliece // Marine Scientist

Mr. McEliece has over 11 years of experience working as a marine scientist specializing in remote sensing, GIS and navigation technologies. He has collected data in both near shore and deep ocean environments all over the world, including North America, Europe, Asia and Africa. Mr. McEliece has the ability and experience to assess client technological and vessel needs, design sampling strategies that streamline project flow and work with all project stakeholders to handle complex projects within time and budget constraints.

Mark Weber // Boat Captain

Mr. Weber is Gravity’s lead marine captain with over 40 years of experience in the industry. Mr. Weber is an expert at navigating river systems and has extensive experience in white water rescue. Mr. Weber has been with Gravity since the beginning and is a critical resource for many of our shallow water operations.

John Schaefer // Fisheries Biologist

Mr. Schaefer is a fisheries biologist with over ten years of field experience. Mr. Schaefer has expertise in offshore survey work, fish population studies, water quality testing, and sediment sampling. Mr. Schaefer has particular experience with shallow water survey programs and has extensive remote sensing and hydrographic and side scan sonar expertise.

Maggie McKeon // Engineer

Maggie has over 10 years of experience as a research scientist and specializes in estuarine hydrodynamics and sediment transport. She has been involved in and led fieldwork in coastal, estuarine, and riverine environments throughout the U.S. and in Europe. She is skilled in designing and executing sampling efforts and analyzing subsequent datasets, additionally she has experience with remote sensing, numerical modeling, and statistical analysis. Ms. McKeon has the technical background and real-world experience to address a client’s scientific and budgetary needs.

Mike Duffield // USCG Captain Lead Environmental Technician

Mr. Duffield has expertise in field sampling programs, fisheries studies, dredge construction management, sediment testing and water quality monitoring. Mr. Dufield has implemented many field studies and has expertise with the techniques for collecting sediment, soil, water, and biological samples. Mr. Dufield is a licensed boat captain and has more than 18 years of marine experience working from Alaska to the Gulf of Mexico and overseas in Russia and Asia.

Jeff Wilson // Environmental Engineer

Mr. Wilson is an environmental engineer with Gravity specializing in sediment and aquatic resource studies. Mr. Wilson provides sediment transport and hydrodynamic modeling support. He has participated in most phases of research studies from the initial design stages to implementation, data collection, analysis, and reporting. He is experienced and effective both in the implementation of sampling designs and efficient, sound data collection in the field. Mr. Wilson is Gravity’s GIS and CAD lead and has extensive mapping and positioning system experience. His cross-skills of both engineering and field implementation make Mr. Wilson a crucial member of the Gravity Team.

Rene Trudeau // USCG Captain and Marine Survey Specialist

Mr. Trudeau is a marine survey specialist with extensive experience in implementing sediment and water quality projects with particular emphasis on vessel logistics and equipment. Mr. Trudeau has expertise in marine construction management, quality assurance oversight, sediment testing programs, and site characterizations using remote sensing. Mr. Trudeau is a licensed boat captain and has more than 15 years of marine experience working from Alaska to the Gulf of Mexico and in remote locations from the South Pacific to Asia.

Shawn Hinz // Managing Partner, Environmental Toxicologist

Mr. Hinz is the senior managing partner at Gravity. Mr. Hinz is the company’s principal research scientist specializing in sediment and aquatic resources with more than fourteen years of experience in the industry. Mr. Hinz has extensive experience in assessing aquatic systems, with particular emphasis on Port and Dredge development programs. He has performed numerous aquatic investigations for both industrial and government clients. He is experienced and efficient in planning and implementing highly technical projects, and dealing with associated strategy and technology challenges.

Pete Jenkins // Environmental Scientist

Mr. Jenkins has over 10 years experience as an environmental scientist with expertise in marine and terrestrial ecosystems and their interactions. He provides a broad range of technical skills and analytical expertise, including field survey protocol design, use of geospatial and remote sensing technology,and the ability to utilize current sampling techniques and technologies for the collection of hydrologic, water quality, sediment and biological data. Mr. Jenkins has significant experience working with stakeholders and regulatory agencies in order to design sampling and monitoring projects that streamline construction issues and minimize study expenses.

Chad Furulie // Marine Operations Manager

Chad manages Gravity’s equipment and vessel fleet and lead’s Gravity’s custom fabrication work with his extensive deisgn and build experience. Mr. Furulie is also and environmental technician with experience in implementing sediment, biological and water quality projects. Mr. Furulie has expertise in HES management,quality assurance oversight, water quality monitoring programs, and biological site characterizations. Mr. Furulie has experience in project management, quality control, design compliance and he is familiar with a wide range of marine equipment.

Emma Rigby // Scientist

Ms. Rigby serves in multiple roles at Gravity, including a marine scientist and assisting with field projects as a field scientist. She specializes in sediment assessments with specialized experience in the biogeochemical cycling of nutrients, dissolved oxygen, and other chemical constituents in marine systems. Ms. Rigby is highly experienced at sample analysis and has worked extensively with large datasets with various statistical approaches to assess data.

Partner Groups and Companies

Ocean Instruments

Ocean Instruments designs and manufactures scientific sampling equipment you can trust. For over 70 years, our products have been used throughout the world by oceanographic research centers, major universities, marine industry, and government agencies.


Claire Dalgliesh // Marine Environmental Survey Specialist

Mrs. Dalgleish is Marine Environmental Survey Specialist with over 20 years of experience in project and survey management,environmental and geochemical field-survey, sample and data analyses and technical report writing. This includes projects based in the UK and overseas, in both coastal and offshore areas. Mrs. Dalgleish is a specialist in Oil &Gas and Dredging regulation, and environmental monitoring standards/guidelines;marine conservation legislation; environmental survey strategies and acquisition programmes; seabed habitat mapping & sampling; cold watercorals and deep sea sponge aggregations of conservation importance, ecology of sensitive/vulnerable habitats, technical ecology input for EISHA and EIA.

Toby Adamson // Oceanographic and Marine Environmental Sureyor

Mr. Adamson is an Oceanographic and marine environmental surveyor with 28 years’experience in metocean and environmental survey fieldwork. Projects he has conducted have been based in the UK and overseas, in a wide range of locationsin both coastal and deepwater offshore environments. Mr. Adamson specializes in Deployment and recovery of metocean equipment in both shallow and deepwater environments.Offshore management of fieldwork studies. On site QA of metocean and environmental data.


Interdisciplinary Initiative in Quantitative Marine Ecology and Environmental Studies


Marine Environmental Impact and Modeling Specialists


Custom aluminum pleasure and work boats. BMF has significant experience building research boats having built over 8 vessels for Gravity and others for local universities and governmental agencies.

Ocean Innovations

Ocean Innovations is a leading supplier of oceanographic equipment. Ocean Innovations represents many of the leading manufacturers of underwater equipment and marine technology. The products we provide are used by oceanographic researchers, commercial, military and scientific divers, hydrographic surveyors, environmental engineers, defense contractors, and the offshore industry.

Perennial Consulting

Darcey Miller // Owner of Perennial Consulting LLC

Darcey Miller is a wetland scientist and Owner of Perennial Consulting LLC, a small firm based in Seattle, WA. Her focuses are on wetland and stream science and restoration, ecological monitoring, wildlife habitat studies, and environmental permitting and planning.