Mystic — The owners of Seaport Marine on Washington Street are proposing a redevelopment of the 11.5-acre site with construction of a second restaurant, a 40-room boutique hotel, commercial space, apartments, townhouses and single-family homes, as well as a public-access boardwalk.

The Stonington Planning and Zoning Commission held a workshop Tuesday night to discuss the proposal with Seaport Marine officials and their attorney Bill Sweeney. They are expected to file a formal application in June, which then would require public hearings.

Seaport Marine and its sister facility, Noank Shipyard, are owned by the Holstein family. They are managed by Abbey Holstein and her husband, Harry Boardsen.

Last week, Boardsen said the project has been seven years in the making, as there has long been a desire to redevelop the Seaport Marine facility.

"This is a total reprogramming of 11 acres of downtown Mystic," he said.

He said the first step was the 2014 construction of the building that now houses the popular Red36 restaurant “to see how things would go.”

While he declined to discuss the total value of the proposal, Boardsen said his project and the $70 million development of the former Perkins Farm site by David Lattizori of Groton are examples of local developers investing in the community.

“We have a stake in this town and in Noank,” he said. “We’re looking to create jobs and new opportunities. Everyone loves Mystic and we’re trying to give them more reasons why.”

The marina will be seeking to use the town's neighborhood development district, a floating zone that was created to spur the development of underused properties, to undertake the project. It would require the marina to obtain approval of its master plan and site plan, both of which require public hearings. Neighbors are expected to raise concerns regarding the project, such as about traffic, as they did with Red36.

Boardsen said the project calls for moving all land-based marina activities, such as mechanical work, boat storage and yacht restoration, to the more modern Noank Shipyard and then tearing down the sheds where that work now takes place. The dock space will remain and be expanded and improved.

He said a second waterfront restaurant, of similar size to Red36, will be built just to the north of it.

Fifty-six housing units would be divided among a multistory apartment building, townhouses and several single-family homes and be built on three separate areas of the site. The 40-room boutique hotel would have a rooftop tapas bar. A sail loft building would house commercial space.

The plan also calls for open space for outdoor events such as corporate meetings and farmers markets. Plans also call for construction of a 1,500-foot-long extension of the Mystic River Park dock that would provide a public walkway that would encircle the marina property and also connect to Washington Street.

Plans also call for construction of a new bulkhead and the creation of a new boat basin with additional boat slips and docks. Parking would be below some of the buildings and in additional surface lots. Parking also would be available for boat slip holders.

Boardsen said the project would be built in phases with the infrastructure, boardwalk extension and new restaurant being completed first. He said the restaurant would create about 150 new jobs.

He said the marina is looking for the lowest level of development density allowed by the neighborhood development district and its design, created by local architect Meg Lyons, would mirror the character of downtown Mystic.

Boardsen said the project would update the property, offer new amenities to visitors, expand public access to the Mystic River and provide millions of dollars in annual tax revenue for the town.

Boardsen said he recently met with shipyard employees, as well as local business leaders and neighbors, to outline the project in advance of the workshop and submission of an application.

Boardsen, who was a member of the Stonington Planning and Zoning Commission for two years, resigned from that position because he said he knew the project would be coming before members and he did not want there to be any questions of conflict.

j.wojtas@theday.com