If the privately owned man-made swimming cove between Diamond Head and Black Point is something the state wants preserved, then the state should own it.

That’s the view of a nonprofit museum that owns Cromwell’s swimming cove and is frustrated that the state Board of Land and Natural Resources in April and May rejected a plan dismantle an outer wall to prevent people from injuring themselves by diving off of it.

The Doris Duke Foundation for Islamic Art sent a letter to the board in June offering to give the state the cove, which was developed by Doris Duke in 1938 as a private boat basin but has long been used by the public for swimming and sometimes dangerous diving that have caused debilitating injuries.

A staff report by DLNR, however, raises “grave concerns” about the offer and strongly urges the board to reject it.

The agency’s board is scheduled to discuss the offer at a meeting this morning.

The foundation had sought permission from the board, which governs submerged lands, to dismantle the cove’s 140-foot-long rock breakwater and scatter the rocks below the inner wall so people can’t jump from either structure. Under that plan, estimated to cost $2.5 million, a narrower area for swimming would remain and be partially protected by a remnant of a basalt dike upon which much of the breakwater was built.

Foundation representatives said the plan was necessary after other efforts, such as putting up a fence, posting signs and hiring security guards, didn’t prevent jumping incidents that resulted in two people becoming paraplegics and one person becoming a quadriplegic.

DLNR’s Office of Conservation and Coastal Lands endorsed the plan, but the agency’s board voted 4-2 in April to deny a permit for the work after hearing public testimony in which Cromwell’s was called a historic place that should be preserved for public use. The board reaffirmed its vote in May, and the foundation asked to have a more in-depth hearing that could involve expert witnesses before any final decision was made.

The offer to give the state the property for free, if accepted, could avoid that contested-case hearing.

The foundation, which was established in 1998 five years after Duke’s death and operates a museum in Duke’s former home known as Shangri La, said its mission has never included supporting public recreation in the former boat basin.

“These submerged lands are currently used solely for public recreation purposes and, as evidenced in recent board meetings, the board is intent on keeping this area open and available for public recreation,” foundation President Edward Henry wrote in the letter.

Henry said there is a clear public purpose for the state to take the property, which Duke received from the Territory of Hawaii in exchange for land that became part of Kailua Beach Park.

The foundation also contends in its letter that it doesn’t legally own the basin but will provide a quitclaim deed to the state that transfers recorded ownership without professing that the title is valid.

DLNR’s staff report argued against a state acquisition, saying it is questionable whether sufficient public purpose exists because the property is difficult to access and the state would inherit liability issues.

“Acquisition by the board would result in the taxpayers of the state underwriting a costly recreational opportunity which would serve only a limited amount of the general public,” the report said. “Under these circumstances, for the board to accept this offer in order to preserve a hazardous condition posing a risk to the public and impose on the state taxpayers a significant liability, would be contrary to the public interest as well as the board’s fiduciary obligations.”