I just saw this post recently after not having seen it for several years.
Don’t fall for this post about an American Flag being hung on a sunken ship at Pearl Harbor, or at ANY other military location, especially as part of a military ceremony.
Just a little research will prove this to be false.

This was a flag that was hung by divers from the Florida Keys National Marine Sanctuary in 2021 to commemorate the 20th anniversary of 9/11. The Vandenberg had NOTHING to do with 9/11.
It was hung from the Gen. Hoyt S. Vandenberg, a former military troop transport and former missile tracking ship that was sunk on May 27, 2009 approx. 7 miles south of Key West International Airport in 140 feet of water in the Florida Keys National Marine Sanctuary. The ship was detonated with explosives and sunk at a cost of $8 million. The Vandenberg has been rated as the number 1 wreck dive in the world by a Scuba Diving Magazine reader poll.
The picture in question was taken in 2014. Their was a lot of noise at the time because many Veterans groups were upset at the violation of the U.S. Flag Code.
If you research all the information at the Pearl Harbor National Monument Archives, you will find there is NOT and never has been, an American flag, placed on any sunken maritime ships, NOR has any ceremony to replace a nonexistent flag ever happened by the National Park Service OR any other military organization.
To place or replace an American flag on a sunken US ship would be a violation of multiple flag codes and has never been practiced by the US military or any known military group.

 

NOT at Pearl Harbor ...  This is the Hoyt S. Vandenberg, a decommissioned naval vessel intentionally sank off of the coast of the Florida Keys. The caption on the meme is a lie.

 

The Vandenberg’s hull was built in 1943 at the Richmond, CA shipyards by the Kaiser Company and launched on October 10th of that year as the General Harry Taylor (AP-145). The ship was transferred to Portland, OR where it was converted to a transport by the Kaiser shipyards in Vancouver, WA. Commissioned on May 8, 1944 at Portland with Captain James L. Wyatt in command, the General Taylor underwent shakedown off San Diego then sailed out of San Francisco bound for Milne Bay, New Guinea with troop reinforcements. The General Taylor continued sailing missions to the Pacific with troops and supplies, bringing veterans home on her return voyages. In June 1945 the ship began service in the Atlantic until the end of the war in Europe. After spending the late 1940s and most of the 1950s on various refugee transport missions, the General Harry Taylor was stricken from the Naval Register on 10 July 1958 and placed in the National Defense Reserve Fleet at Beaumont, Texas.

In July of 1961, the General Harry Taylor was transferred to the U.S. Air Force. She was renamed the USAFS General Hoyt S. Vandenberg on June 11, 1963. The U.S. Navy acquired the Vandenberg on July 1, 1964 and designated her as T-AGM-10, a missile range instrumentation ship. The Vandenberg was equipped with extremely accurate radar and telemetry equipment, then deployed to Dakar, Senegal in 1974 to begin duty tracking and analyzing the re-entry phase of ballistic missile test flights. The ship carried out missile and spacecraft tracking duties in both Atlantic and Pacific waters until her retirement in 1983. The Vandenberg was stricken from the Naval Vessel Register on 29 April 1993.

 

The USNS Hoyt S. Vandenberg (T-AGM-10)

Transfer of the Vandenberg from the Maritime Administration to the state of Florida for use as an artificial reef was approved in February 2007. After preparation for sinking, the ship was towed to Key West and arrived in the Key West Harbor on April 22, 2009. 

 

The Vandenberg was sunk on May 27, 2009 to end up resting with the main deck 100 feet down and the upper decks and super structure 47 feet below the surface. As the second largest artificial reef in the world, the ship has become home to hundreds of species of fish, coral, and other marine life forms.

 
 

The Sinking of the Gen. Hoyt S. Vandenberg
Florida Fish and Wildlife Conservation Commission
https://www.youtube.com/watch?v=WTtog2zl7qw

 (Incidentally, a Conch Republic flag was flown from the ship after it was first sank.)