A dispute over plans to expand a pier on the Bar Harbor waterfront could blow over in a few days. But for the present it has brought the job to a standstill and led to some dark suspicions. An agreement to provide details on the building’s size and exterior look, while withholding security details, offers the best way forward.

The impasse started when applicants for a permit to double the size of an existing pier at the Harborside Hotel and Marina refused to give the Bar Harbor planning board detailed plans for a ship passenger screening building. They said the Coast Guard had told them not to. Perry Moore, representing Harborside owner Tom Walsh and chief architect for the job, told the board: “They’re not the kind of documents the Coast Guard wants us to circulate to the public, for obvious reasons.”

The board chairman, Kay Steven-Rosa, insists that the board must examine the plans for the building regardless of any reported restriction. Aside from maintaining the board’s authority, she told the Bangor Daily News that she wanted to make sure the building would not turn out to be simply a trailer. She said, “The diagram we got looked like a place holder and not a real building.”

Mr. Moore said he had asked the Coast Guard for a statement in writing about the impact of its guidelines on whether the plans should be given to the board. He said other town officials such as the harbormaster, the code enforcement officer and the fire chief would have access to the plans to make sure they met local and state standards. Planning board proceedings are open to the public, however.

Coast Guard officers and spokesmen have said repeatedly that the agency had not placed any limitations on releasing information about the pier expansion.

But Lt. Cmdr. Michael Lingaitis, assistant chief of the Preventions Department at the Coast Guard’s Portland station, says the passenger-screening building might contain electronic security systems that should not be disclosed to the general public. He says such details should be withheld and shown only to qualified officials, while structural details of the building could be provided to the planning board and to the public.

The building is intended mainly to provide screening facilities for the thousands who arrive in Bar Harbor on the huge cruise ships, most of which have already undergone screening at another U.S. port.

So Ms. Stevens-Rosa is right in demanding access to the building plans and rejecting what she called the “terrorism-is-the-reason” excuse for secrecy. But that must be balanced against the fact there will be security systems or devices that may legitimately be withheld.