The vintage 63-foot “admiral’s barge” operated by U.S. Pacific Fleet for dignitary visits, two smaller boats, and the boathouse in which they are housed were damaged by an early morning fire on Sunday, the Navy said.

President Barack Obama and Japanese Prime Minister Shinzo Abe rode in the stately mahogany-hulled boat that bears the name “CINCPACFLT” (Commander in Chief, Pacific Fleet), in December 2016 as part of Abe’s visit to the USS Arizona Memorial following the 75th anniversary of the Pearl Harbor attack.

The blue-and-white admiral’s barge, constructed in 1957, is the last 63-foot rescue boat still in military service, according to Carlos Ruth, who runs the website uscrashboats.org.

“It’s a historic boat. The few people that know about it are kind of upset with what happened because it is a historically significant boat,” Ruth said.

President Donald Trump, accompanied by first lady Melania, boarded the CINPACFLT for the trip to the USS Arizona Memorial on Nov. 3, 2017, he said.

Ruth said on his website that “early indications are that it was arson. Unofficial reports also indicate that security was poor and that closed-circuit cameras were old and inoperable.”

Pacific Fleet spokesman Lt. Cmdr. Tim Gorman said the Navy is investigating, but he could not speak to the arson report.

He said that at about 3 a.m. Sunday, the Federal Fire Department and the Honolulu Fire Department responded to fire and smoke observed at the Pacific Fleet boathouse in Aiea Bay.

The fire, which was under control around 6:15 a.m., damaged the boathouse and three barges. No one was injured.

Ruth said on his website that the CINCPACFLT was built by Knutson Shipbuilding in Halesite, N.Y., and was one of nine boats built for the Navy under its last contract for 63-foot air-sea rescue boats. It was built with double planking with Honduras mahogany on the exterior and cedar on the interior, he said.

In 2011, the admiral’s barge underwent $142,000 in repairs and upgrades, Ruth said.

According to the AVR Society (short for air vehicle rescue), the Navy boats were designed during World War II, and compared to the better-known PT boats, were relatively lightly armed.

“Their role was to swoop in fast and retrieve downed airmen in the Pacific, Atlantic and Mediterranean waters,” the website said. Ruth said the vessels were nicknamed “crash boats.”

Photos after the fire showed the CINCPACFLT with some superstructure charring, but still floating. Asked if the boat is repairable, Gorman said, “I don’t know that at this point. I just know it’s under investigation and (the boats) are down for now.”

The two smaller boats are the deputy commander’s barge and a remembrance barge used frequently for historical tours of Pearl Harbor, Gorman said. Those tours have now been canceled, he said.

The Quonset hut-style boathouse received some damage, but a small attached museum with framed pictures and a model of the USS Arizona is believed to have been spared.