The only sound one recent weekday morning at Tide Point was the whir of a clamshell crane’s chain as it clawed sugar from a barge into the Domino Sugar refinery.

Three people quietly did yoga on a public pier. A kayaker glided by. But the buildings near the waterfront sat mostly vacant and silent.

Tide Point, a slice of land jutting into the Patapsco River in the northern part of Locust Point, has been a ghost town since Under Armour relocated to the Baltimore Peninsula last year. Its future remains undetermined, but its next likely owner is known: Developer Mark Sapperstein of 28 Walker is buying the 12 acres of former Under Armour property for a mixed-use development.

Apartments, office space, retail and a hotel are all possibilities.

“I’m trying to give myself a bunch of options,” Sapperstein said.

He and Under Armour confirmed they have entered into an agreement, declining to specify the price. They are in the “due diligence” stage, and the deal is not final. Once it is, Tide Point would become the latest Baltimore waterfront property to be redeveloped — again.

Originally the site of a Procter & Gamble soap manufacturing plant, Tide Point was transformed in 2004 into an office complex that became the headquarters of the fast-growing athletic apparel maker. Under Armour bought the buildings in 2011.

Sapperstein’s purchase comes after he bought a nearby parcel south of Key Highway. That property, a warehouse known as the Cheer Building and located at 1450 Beason St., had been controlled by Cross Street Partners, a Baltimore-based real estate company, and leased to Under Armour.

Although Sapperstein initially wanted to develop rowhomes there, he said he plans to sell that land to Cristo Rey Jesuit High School, which would relocate from Upper Fells Point into the renovated warehouse.

Cristo Rey is part of a national network of 40 private schools primarily serving low-income students of color, and its students pay a modest tuition (the national average is $882 per family) and work part-time jobs. The school, which did not reply to a request for comment, also raises money through donations.

Sapperstein purchased the Cheer Building’s seven acres of land for $2.5 million this year, state property records show. However, he said he scrapped plans to build 120 town houses there because he never got on the same page with a task force created by the Locust Point Civic Association.

“We hit this headstrong issue about parking and design,” he said.

Locust Point Civic Association leaders said they aren’t sure why the town house development fell through but are optimistic for what Sapperstein generally has planned. Still, it’s hard to offer full support, said Caitlin Regan, the association’s vice president, when they’ve been “kept in the dark” on the breadth of the vision for all of Tide Point.

“We want to be excited about things,” she said, “but we want to be cautiously optimistic because this was a plan for rowhomes. Now it’s going to be a school and we got caught in the crosshairs.”

As part of the transformation of the warehouse into the school, Sapperstein said, a section of the property would be converted into a sports field.

Schools aren’t currently permitted in the area, according to a planned unit development. Baltimore’s Planning Commission voted this month to allow schools, and it ultimately will be up to the Baltimore City Council to amend the PUD.

“We think this is a great adaptive reuse,” said Caroline Hecker, an attorney representing 28 Walker, during an Aug. 7 commission meeting.

Regan said the school seems like a positive for the community, but the civic association wants to learn more about plans. The association will discuss the change to the PUD at its next meeting in September.

Councilman Zac Blanchard, who represents the area, said Sapperstein’s plans to develop Tide Point would include improvement to the water taxi stop and keep the nearby pier available to the public.

Regarding plans for the Cheer Building, Blanchard was on board with it becoming town houses but also supports converting it into a school.

“Cristo Rey is an absolutely phenomenal asset for Baltimore City,” he said. “I am really excited about the potential of them moving into the 11th District, both for the school and because of the sports field, which would be a huge asset to the neighborhood.”

Tide Point is named for Tide laundry detergent, and its brick industrial buildings served as a soap plant for much of the 20th century. Procter & Gamble’s old logo is visible on some of the exteriors of the five buildings, which are named for products: Tide, Dawn, Ivory, Cascade and Joy.

Banner reporter Maya Lora contributed to this article.