The captain of the naval hospital ship involved in a collision with the World War II memorial in Pearl Harbor is a former sailor who retired with multiple decorations.

The master of the USNS Mercy -- the equivalent of the commanding officer -- is Capt. Thomas Giudice, a retired sailor and current civilian mariner who's responsible for navigating the vessel while underway at sea, among other duties, a Navy official said.

The 894-foot-long, 69,000-ton hospital ship, or possibly one of the two tug boats transiting her out of the harbor, struck the USS Arizona Memorial in Pearl Harbor early Wednesday morning. Tours of the memorial, which gets more than 4,000 visitors a day, were suspended until June 4 because of the accident.

"We're still offering modified tours," said Abby Wines, public information officer for the National Park Service, which manages the historic site. "Visitors can still view the memorial; they just can't set foot on the memorial for safety reasons."

The floating dock to the white building that spans the mid-portion of the sunken battleship was badly damaged after being pushed almost 10 feet. The dock, ramp and railings were later removed by work crews using a crane. Divers continue to inspect the 184-foot-long memorial, where some concrete cracked, as well as the sunken ship, which wasn't impacted.

"That's great news," Wines said of the World War II-era battleship. "That's the most important thing -- that the Arizona wasn't damaged and that no one was injured because this happened before the first tour was out there."

The Mercy, meanwhile, also wasn't damaged and left the port later in the day en route to a planned four-month exercise in the Asia-Pacific region known as the Pacific Partnership 2015.

Because the hospital ship is part of the service's Military Sealift Command, it doesn't have a traditional Navy command structure. Uniformed military personnel run the vessel's hospital, known in naval parlance as a military treatment facility, or MTF, while civil service mariners operate the ship itself and are responsible for navigation, deck operations and engineering duties.

While Navy Capt. Melanie Merrick is the commanding officer of the ship's medical treatment facility, Giudice is the captain of the ship itself. He was named master of the USNS Mercy in November 2013 when the vessel was activated to support emergency relief efforts in the Philippines following Typhoon Haiyan, according to his profile on a website for Pacific Partnership 2015.

A Long Island native, Giudice retired from the Navy as a senior chief quartermaster, his profile states. During his time in the sea service, he received multiple awards, including the Meritorious Service Medal, Navy Commendation Medal, three Navy Achievement Medals, Navy and Joint Meritorious Unit commendations, among other awards, it states.

In 2000, Giudice joined the command as an able seaman, according to the bio. He later acquired a U.S. Coast Guard master's license and beginning in 2011 was assigned command of ships, including the USNS Bridge and USNS Richard E. Byrd, both on extended deployments in the Arabian Gulf and Gulf of Aden, it states.

At the time of Wednesday's accident in Pearl Harbor, the hospital ship was under the direction of a pair of tug boats to guide the vessel out of the harbor. The names of the tug boat captains -- civilian contractors who work for the Honolulu-based Navy contractor P&R Water Taxi -- weren't available as of Thursday afternoon.

In addition, it's unclear what role the harbor pilot played in the incident. The harbor pilot, who also hasn't been identified, is charged with helping ships enter and exit the port. He or she typically does so by boarding the ship and helping to guide it through the waters by communicating with the tug boat captains.

Meanwhile, the top Navy official responsible for all port operations in Pearl Harbor is Rear Adm. Richard Williams, commander of Navy Region Hawaii and Naval Surface Group Middle Pacific.

The USS Arizona Memorial is the final resting place of most of the ship's 1,177 crewmen, who were killed during the Japanese surprise attack on Pearl Harbor on Dec. 7, 1941, according to the National Park Service. The accident came just days after the Memorial Day weekend, a busy time of the year for the site, which receives some 1.6 million visitors a year and 4,300 a day.

"The line when we opened this morning in just as long as it normally is," Wines said, noting that the site hit its daily capacity of 4,350 visitors taking boat trips to the memorial. "I'm grateful for how patient and understand the visiting public has been."

-- Brendan McGarry can be reached at Brendan.McGarry@military.com