A US Navy sailor who is believed to have fallen overboard off the coast of Australia has been declared lost at sea. 

Jose Antonio Rivera Lynch IV, 19, vanished from the USS George Washington vessel on July 28.

The 19-year-old from Middleburg, Florida, was serving as an aviation boatswain’s mate on an aircraft carrier when he went missing.

Just hours before his presumed fall overboard, his heartbroken parents shared that they had a ‘positive’ phone conversation about his life.

However, they noted he mentioned feeling fatigued from long days on the ship. His father, Juan, told News4Jax he ‘noticed his tiredness’.

‘I told him, “You’re the best of me. You’ve been to places I’ve never been and we are so proud of you,”‘ he remembered. ‘Those were the last words I said to my son.’

After Rivera Lynch went missing from the carrier, an urgent search-and-rescue operation was initiated, covering over 2,200 square miles with the involvement of several other US Navy vessels.

The Australian Defense and Australian Border Forces also joined the search, but after 45 hours, officials called it off. Rivera Lynch was declared deceased on August 1.

US Navy sailor Jose Antonio Rivera Lynch IV, 19, was declared lost at sea after he is believed to have fallen overboard off the coast of Australia on July 28 

The 19-year-old, from Middleburg, Florida, was an airman on the USS George Washington aircraft carrier 

Rivera Lynch’s family said he, ‘faithfully served his country with honor, courage, and an unwavering commitment to protecting others.’ 

‘Jose was more than a sailor — he was a loving son, a cherished brother, and a loyal friend whose laughter and light touched everyone around him,’ they wrote on a GoFundMe.

‘His sudden loss has left our family heartbroken and navigating the unimaginable grief of losing someone so young and full of promise.’ 

His father added that his son came from a long line of military servicemen, also including his grandfather and sister. 

‘He is my hero,’ the grief-stricken father said. 

‘He was vibrant, educated, humble. He served his country, he served the Navy and he has made his family proud.’  

The sailor’s parents said they spoke to him over the phone just hours before he fell overboard, and described him as ‘vibrant, educated, and humble’

Rivera Lynch first enlisted in the military as a 17-year-old in high school. He joined the USS George Washington (pictured) in January and was on board off Australia as it sailed through the Timor Sea when he went missing

Rivera Lynch first enlisted in the military as a 17-year-old in high school, and joined up as part of the Navy’s delayed enlistment program. 

He joined the USS George Washington in January and was on board off Australia as it sailed through the Timor Sea when he went missing. 

In a statement after the airman was declared dead, Carrier Strike Group 5 commander Rear Adm. Eric Anduze paid tribute to the young recruit. 

‘Our thoughts and prayers remain with Airman Rivera Lynch’s family, friends, and shipmates during this incredibly difficult time,’ he said. 

‘The courage and dedication shown by all personnel involved in this operation exemplifies the professionalism and commitment that defines our Navy.’