John Graham

Director, Co-Founder

Mr. Graham began diving commercially in 1973 after graduating from Divers Institute of Technology. He has more than four decades of experience in ship repair, salvage, marine construction and pipeline installation utilizing air and mixed gas diving techniques. His career with Global took him to jobs in the North Sea, the Gulf of Mexico and throughout the United States. One of Global’s original founders, Mr. Graham continues to grow the company through his active involvement in operations through client and staff engagement.

Industry Associations:
• Propeller Club
• Puget Sound Maritime Historical Society, Contributor
• Society of Petroleum Engineers
• Society of Port Engineers

Timothy Beaver

Director, Co-Founder

Mr. Beaver began his career as a commercial diver after graduating from Divers Institute of Technology in 1977, and also holds a BA from the University of Utah. He dove on a regular basis for more than 30 years, working on projects from ship repair and salvage to marine construction and pipeline installation. As one of Global’s directors, Mr. Beaver continues his involvement in the company through client relations.

Industry Associations:
• Association of Diving Contractors International – Board of Directors
• American Salvage Association
• Historical Diving Society – Board of Directors
• Propeller Club
• Puget Sound Maritime Historical Society – Contributor

Executive Leadership

Devon Grennan


Mr. Grennan joined Global in 1995 and grew up in the business by serving in a variety of roles including Marine Environmental Supervisor, Environmental Division Manager and General Manager. He was appointed President in 2009 and added the title of Chief Executive Officer in 2013. He also serves on Global’s Board of Directors. Mr. Grennan’s primary role is to implement Global’s strategic plan, including development of partners along the West Coast and abroad, and the expansion and growth of Global’s core strategic service lines. His passion is looking for ways to introduce younger generations to the maritime industry, and he is proud to continue his family’s history of working on the water. He holds a Bachelors of Science degree from the University of Washington, and admits to being a law school dropout.

Industry Associations:
Spill Control Association of America, President
Vistage, Seattle
Propeller Club
The Beavers

Dan Pierson

VP of Operations

Mr. Pierson began diving for Global in 1992, working as a diver/tender, saturation diver, Dive Supervisor and Dive Superintendant before moving into management roles, first as Asset Manager, then Vice President of the Pacific Northwest Region. He was appointed Vice President of Operations in 2014, and is responsible for overseeing all of Global’s regional offices as well as corporate asset management. Mr. Pierson earned his commercial diving certificate from the Divers Institute of Technology in 1991 and honed his skills working in the Gulf of Mexico.  He grew up on the water and has been involved with recreational boating and diving all of his life, and it continues to be a passion of his today.  Mr. Pierson says although he never wanted to grow up and take an office job (“You miss one meeting and your future is planned for you…”), he feels very fortunate to have worked with so many incredible people over the years, both in the field and in the office. “Global has come a long way during my time here, and I’m excited to see where we take it next.”

Industry Associations:
Association of Diving Contractors, Inc., Board of Directors
International Marine Contractors Association
Divers Institute of Technology, Program Advisory Committee Member
The Beavers

Jennifer Jensen

VP of Quality Assurance

Ms. Jensen joined Global in 2013 as head of the Quality Assurance Group, which encompasses Human Resources (HR), Health, Safety and Environmental (HSE), Compliance, Certifications, Contracts, and Professional Development. She ensures these groups are responsive to the needs of our clients, our operations and our employees. Ms. Jensen holds a BA in Business Administration from Eastern Michigan University; she also holds SHRM-CP and PHR certifications. Prior to working at Global, she gained experience in the airline, higher education and retail industries, holding a number of management positions including Director of Human Resources.

Industry Associations:
Society for Human Resource Management
Association for Talent Development
The Risk Management Society
Lake Washington Human Resources Association
World At Work

Trinity Ng-Yeung

VP of Finance & Administration

Ms. Ng-Yeung joined Global in 2004, quickly rising to the position of Controller; in 2009 she was named Vice President of Finance & Administration. She heads Global’s accounting team and sets protocols and policies for the administrative staff. Her responsibilities include audits, budgets, financial forecasts, aligning strategies between departments and regions, and the ongoing development of Global’s accounting systems. Ms. Ng-Yeung holds a BA in Accounting from Portland State University. Prior to working at Global, she provided accounting services for both the public and private sector.

Industry Associations:
American Institute of Certified Public Accountants
Women’s International Shipping & Trade Association

Mike Langen

VP of Marine Construction, Engineering, & Technology

Mr. Langen has over 30 years of experience in the industry as a diver, engineer and manager. After several years working as a commercial diver he returned to school and earned a Bachelors of Science in Ocean Engineering from the University of Washington. After graduating, Mr. Langen worked as a design engineer and project manager developing ROVs and other underwater systems and tools. In 1998, Mr. Langen rejoined Global Diving & Salvage, Inc. to organize and market the company’s growing inland marine construction business, developing it into a competitive and nationally sought after business line. As Vice President of Marine Construction, Engineering and Technology, Mr. Langen is responsible for project management, engineering support, bid evaluations, cost estimating and field operations of the marine construction service line, as well as operation of the ROV Division. He also oversees a full time support services group focusing on in-house engineering and design.

Industry Associations:
The Beavers