Did JFK jr and Caroline use USS Essex ship as an exit plan ?

 John F. Kennedy Jr. and Carolyn Bessette-Kennedy used the USS Essex as an escape plan. However, we should distinguish that claim from the documented history of the Kennedy family and the US Navy.

JFK Jr. and Carolyn Bessette-Kennedy: On July 16, 1999, they departed New Jersey in a private aircraft piloted by JFK Jr. His sister-in-law, Lauren Bessette, was also aboard. The plane crashed into the Atlantic Ocean near Martha's Vineyard, killing all three. The official investigation attributed the crash to spatial disorientation. 

The USS Essex: The US Navy's historical records show that the aircraft carrier served during World War II and later conflicts. It was decommissioned in 1969. 

The Kennedy family's naval connection: Caroline Kennedy and her brother, John Jr., visited the aircraft carrier USS John F. Kennedy in 1970. That is a documented family connection to a different ship. 

The ship used for their burial at sea: After their deaths, their ashes were committed to the ocean from the Navy destroyer USS Briscoe in a private ceremony on July 22, 1999. 

It could be a conspiracy theory, a misunderstanding involving different naval vessels, or a claim circulating on social media. I haven't found reliable evidence establishing that the couple planned to escape aboard the USS Essex.