Sutherland Shire Historical Society is opposed to plans for a four-storey training academy for marine rescue services on Hungry Point Reserve, Cronulla.
However, the trust which manages the site of the former fisheries research centre which the state government closed in 2014, supports the move.
Heritage NSW, whose role is to protect and manage heritage across the state, has called for public submissions.
Under the plans, the former fisheries administration centre would be demolished and replaced with a four-storey training academy including single-room accommodation, conference and dining facilities.
A training pool and facilities would replace the former fisheries aquarium on the edge of Gunnamatta Bay.
Three buildings would need to be demolished and two others refurbished.
John Rayner, chair of the Hungry Point Reserve Land Manager (the trust), said it supported the proposal.
"Through the development of the academy, heritage listed structures will be restored and occupied," he said.
"In addition to improving the skills of emergency services personnel it will bring jobs and benefits to the local economy.
"The development proposal has been submitted independently of the trust and the board is now reviewing plans it is seeing for the first time.
"I encourage residents to have their say on the proposal for this heritage listed site."
Pauline Curby, president of the Sutherland Shire Historical Society, said Building 10, the former fisheries school / laboratory was heritage listed and should not be demolished.
"Building 16, the former administration building, is not heritage listed and, while it can be demolished, the construction of a four-storey building in its place will be out of character with the site, especially its proximity to the heritage listed Buildings 13 and 15, which provided migrant hostel accommodation," she said.
"A better solution for this part of the site would be to turn this area into green space and plant appropriate native species plus interpretative signs about the migrant hostel history as this is the area where the other 16 migrant hostel buildings, which have since been demolished, were located.
"This would maximise the magnificent views helping visitors understand why migrants who were accommodated at Hungry Point considered they were in the best hostel in Australia."
Ms Curby said a 2012 report by government-appointed consultant David Harley on future uses for the site recommended it remain in public ownership, and that there should be no large-scale commercial or hotel development.
"SSHS has consistently supported these principles," she said.
The move to establish Australia's first dedicated training facility for marine rescue services was announced by the state government in 2020.
Funding of $12 million was promised for the centre, to be used primarily by the largely volunteer organisation, Marine Rescue NSW, which has been based at Hungry Point since 2013.
The centre would also be available to other emergency services from NSW and interstate, whose members use vessels as part of their operations.
Catering for up to 100 trainees a week, it will include a large lecture/meeting room, smaller classrooms equipped with marine simulators and other technological learning tools, practical outdoor training areas, accommodation and meal facilities.
Submissions to Heritage NSW, which can be made online, close on September 21.
Visit: https://www.heritage.nsw.gov.au/applications/state-heritage-items/have-your-say/