Reactivation of a 6-acre dry dock on the South Boston waterfront is expected to include proposals for parkland and a cruise ship “floating hotel” berth, as Boston officials consider ways to expand public access to the waterfront.

The Boston Planning and Development Agency will seek proposals from developers this spring for ways to reuse the abandoned dry dock No. 4, which is currently restricted to maritime commerce uses.

Developers Brent Johnstone and Tim Allcott of Boston Dockside Group told The Boston Globe they want to convert the pier behind the Blue Hills Bank Pavilion into a marine terminal including docks for water taxis and recreational boaters, along with a cruise ship that could provide up to 500 rooms as a “flotel.”

The Trustees of Reservations conservation group has been studying the dry dock’s potential for use as a public park and is expected to submit a proposal as well.

Future uses for the pier are studied in the BPDA’s updated master plan for the 191-acre Raymond L. Flynn Marine Park, which covers the eastern end of the Seaport District. Because of its dilapidated condition, the dry dock needs $6 million in repairs to be reactivated for marine industrial or commercial uses, according to the master plan update report. Citing the lack of demand for marine uses, the report suggested the property could be filled in as a development site or provide a mix of open space and water-dependent uses similar to Long Wharf.

The report concluded that more flexible zoning could encourage more than 4 million square feet of additional development in the park, which is owned by Massport and the Economic Development and Industrial Corp. of Boston.