The third Marine killed when a US military aircraft went down in waters off the central Queensland coast has been identified as 19-year-old Ruben Velasco from California.
A GoFundMe page has been started by Mr Velasco's family to fund his funeral arrangements.
His father Ray Calzada shared a tribute on Facebook saying the family was in disbelief and couldn't "fathom the loss of our son".
"My heart is broken for our families' loss," he wrote.
"Ruben is loved so very deeply and he will be missed by everyone who had the honor of knowing him."
Osprey crew chief Corporal Nathan Ordway, 21, of Kansas and Lieutenant Benjamin Robert Cross, 26, of Maine have been identified as the other Marines who were killed in the crash.
Head of expeditionary force Colonel Tye Wallace said the loss is felt across the entire Marine Corps family.
"To the families of the brave Marines we lost - there is no way for us to understand what you are going through," said the colonel.
"What we do know is that your Marines left a lasting impression on the 31st MEU, the Marine Corps, and the world. They will live on forever in our thoughts and our hearts. You will always be a part of the Marine Corps family, and you will remain in our prayers."
The tilt-rotor MV-22 Osprey with 26 people on board, plunged into the sea at Shoalwater Bay, near Rockhampton, during a scheduled military exercise on Saturday.
One Marine remains in a Brisbane hospital after being airlifted from Rockhampton after the crash.
Australia's HMAS Melville located the submerged aircraft on Sunday night.
An Australian navy clearance diving team commenced operations with an underwater remotely operated vehicle on Monday.
Defence Minister Marise Payne told Senate question time the recovery operation was complex and would be affected by factors such as the state of the wreckage, weather conditions and water current.
"The focus will be of course on finding and recovering the three missing marines, then on retrieving crucial equipment such as the flight data recorder which will aid in accident investigation," she said.
A US salvage vessel is en route to Shoalwater Bay.