Year after year, the highlight of the summer vacation for former State Sen. Vincent J. Fumo was a free cruise on a luxury yacht on the waters between Martha's Vineyard and Nantucket.

He and his closest friends sailed on the historic, long-hulled Principia or Enticer, all expenses paid by a Philadelphia maritime museum.

When the museum's yacht was in the boatyard, the Independence Seaport Museum even leased a substitute for Fumo, the Sweet Distraction.

Yesterday, in a sterile federal courtroom far from gulls, sails and sea, Fumo took notes on a yellow legal pad while prosecutors and the Philadelphia Democrat's defense team quarreled over the legality of those cruises.

The government says those trips needlessly cost the museum $100,000, and prosecutors argued that Fumo and the museum's disgraced former president, John S. Carter, had conspired to defraud the museum with the cruises.

The defense contended that there was no fraud because Carter had a right to hand out such a freebie to board members, including Fumo.

Defense lawyers also argued that Fumo had not been alone in getting special treatment from Carter.

According to the defense, another board member got a one-time 35 percent discount on a cruise, and a former member received a 50 percent cut.

Prosecutors contended, however, that Fumo was unique in his greed, that he alone among the two dozen board members had gotten totally free trips worth thousands of dollars each August from 1996 to 2003.

To portray Fumo as a usurper of museum services, prosecutors called to the stand two of his fellow Seaport board members and three of his oldest friends, buddies he had invited to cruise with him.

The friends testified that the trips had been primarily social, not efforts to boost the museum, as the defense has contended.

Ann Catania, owner of the Ten Pennies flower shop on North Broad Street, acknowledged that she had told a grand jury that Fumo referred to the trips as vacations. Her husband, Gerald, testified that Fumo had never asked him to give to the museum, and that he had never given.

The board members said they hadn't known that Fumo sailed for free until news broke that the FBI was investigating the trips.

Board member John F. Meigs said his law firm had paid to use the Enticer in 2003 and 2004 to entertain clients.

To use the boats "for a private purpose without paying would not be appropriate for a board member," he testified.

He and another witness, M. Walter D'Alessio, who was the museum's board chairman during the years Fumo sailed, also noted that the museum's official ethics statement says board members may use its only property for "official purposes" and "may make no personal use" of museum assets.

In rebuttal, defense lawyers argued that this section was trumped by later language in the document that says no one can use the museum's assets in a "non-museum matter . . . without the express prior consent of the president."

Fumo's lawyers said he had not engaged in fraud because Carter had known of his trips.

In a sense, Carter is the elephant in the courtroom. He is serving a 15-year federal prison sentence on charges that he stole $1.5 million from the museum, which he led for 17 years.

Fumo had no connection to those crimes.

U.S. District Judge Ronald Buckwalter has forbidden witnesses and lawyers to mention Carter's 2007 guilty plea for fear such testimony would be unfair to Fumo.

Contact staff writer Craig R. McCoy at 215-854-4821 or cmccoy@phillynews.com.