As a Belgian native, Greta Wagle attended the Catholic University of Leuven and earned a Master’s degree in Dutch and English Linguistics and Literature. Upon graduating, she began her career teaching Dutch and English as a high school Language Arts instructor at Instituut H. Graf in Bilzen, Belgium, and Ursula Instituut in Herk-de-Stad, Belgium. In 1978, Greta Wagle emigrated to the United States to teach French at Lincoln School in Providence, Rhode Island, and concurrently worked as a private Dutch tutor. She eventually moved to New York, where she currently resides.
After many years as an educator, Greta Wagle decided to focus on research. As an independent researcher, her projects are primarily centered on 17th-century Dutch history and involve topics such as New Netherland history, Dutch language history, games and entertainment in the Low Countries, Dutch maritime history, and shipbuilding techniques. Greta Wagle participated in the New Netherland Institute, a nonprofit program at the New York State Library dedicated to translating the official 17th-century Dutch records of New Netherland. In addition, she collaborated with historical societies, organizations, and house museums in Albany, New York to translate, identify, and catalogue Dutch artifacts. She also served as a researcher, editor, and proofreader for the preparation of three encyclopedias and other educational materials. However, her most prominent accomplishment is The Onrust Project.
In 2005, Greta Wagle became a founding member of The Onrust Project, an endeavor involving 17th-century Dutch shipbuilding techniques aimed at reconstructing The Onrust, the first yacht built in the New World. As the Project Director, she initiated and coordinated the project with founding member Don Rittner, assisted by a core team of thirty volunteers. In addition, Greta Wagle assumed responsibilities such as planning construction, organizing daily work schedules, communicating with the design team, arranging materials acquisition and transportation, and fundraising. In May 2009, the ship was launched into the Mohawk River from the Mabee Farm Historic Site in Rotterdam Junction, New York, where it was built.