Norwich ― Thayer’s Marine finally might be done with the expansion projects that have cemented its boat sales, service and retail operations at the junction of West Main Street and Falls Avenue.

“There’s nowhere else to expand,” owner Richard Thayer said Thursday during a celebration Thursday to mark completion of the family-owned business’ $800,000 renovation of a decaying former warehouse into a boat showroom and service center.

Now called Thayer’s Marine West 28, the 3,000-square-foot building at 28 Falls Ave. houses about 20 boats either for show or being serviced. The warehouse, just a few feet from the Norwich Transportation Center, had been abandoned and slated for demolition by the city.

Across Falls Avenue, the main operation includes a retail marine supply store, additional showrooms, service and storage areas and related businesses, all in renovated and repurposed old buildings along the east and west branches of the Yantic River near Norwich Harbor. The work has taken years to complete.

Thayer’s Marine was established in 1966, originally on a portion of the grounds of the current Marina at American Wharf and is one of the longest running downtown Norwich businesses.

For the latest project, the Norwich Community Development Corp. awarded Thayer’s Marine a matching grant of $240,043 toward what Thayer initially estimated would be a $486,000 project. But Thayer and his wife, Dolores Thayer, laughed off that estimate, saying the total ended up nearly twice that at $800,000.

About two dozen city and NCDC officials, Thayer’s Marine employees and family members gathered for Thursday’s official presentation of the check from the Norwich Revitalization Program.

Funded through the city’s federal American Rescue Plan Act grant, the program dedicated nearly $2.5 million for economic development projects through matching grants. Only about $60,000 remains unallocated, NCDC President Kevin Brown said.

Brown and Mayor Peter Nystrom thanked the Thayer family for its dedication to the city of Norwich and continued expansion projects. The company has about 25 employees.

“A longtime business here in town, and that counts,” Brown said of why Thayer’s was selected for the grant, “because part of this is ensuring that we keep businesses in Norwich that have been loyal to Norwich. So we stand here today with a revitalized building that helps expand the capacity for a great Norwich business owner, and we’re proud to do it.”

Nystrom noted that the Thayer’s Marine’s location on the manmade Hollyhock Island that splits Yantic River into east and west branches, doesn’t have the best view. The city’s sewage treatment plant looming in the distance is also undergoing a major renovation project.

Thayer thanked several city departments and Norwich Public Utilities for their assistance, despite numerous disputes with some of those departments on how the project should be done. Thayer called Nystrom “the referee” between himself and the city regulators.

Thayer then pointed to his family, thanking son Richard Thayer III for running the business while he embarked on “one of my projects,” and daughter, Rachel Thayer-Tarner for her artistry in designing the business logo and making the new sign for Thayer’s Marine West 28. Thayer-Tarner, who works at the business in marketing and sales and designs detailing on boats, did the paperwork for the grant application.

“Take a moment and look at this,” Thayer said. “Another piece of Hollyhock Island has been restored. I am proud of what the city and I have been able to accomplish when working together. We have not even fully transformed into this space, but it has already helped Thayer’s Marine grow.”

c.bessette@theday.com