The sons of late British businessman and adventurer Hamish Harding remembered their father as a "loving" man with a "larger-than-life presence." 

Harding, the billionaire founder of Action Aviation, a UAE-based international aircraft brokerage company, was one of five crewmen who perished aboard OceanGate Expedition's Titan submersible on an ill-fated voyage to see the Titanic wreckage. He and the others died when the submersible suffered a "catastrophic implosion" shortly after the craft descended to the Titanic, the U.S. Coast Guard said. 

Action Aviation released statements from Harding's sons giving tribute to their father on social media. 

MISSING TITANIC SUBMARINE FOUND, CREW KILLED IN DEEP-SEA CATASTROPHE, COAST GUARD SAYS

Hamish Harding

Hamish Harding poses for a photo during the RMS Titanic Expedition Mission 5 on Sunday, June 18, 2023. The U.K. billionaire was remembered by his sons as a "loving father" and inspirational adventurer.  (@actionaviation/Twitter)

"My dad was a tenacious, hard-working businessman but most importantly he was the best father I could have ever asked for," said one son. "He inspired me more than anyone will ever know, taught me things I'll never forget, and he meant everything to me. Anyone who ever met my dad will praise his humorous personality, his sheer work ethic, and his constant generosity. My life will be a success if I'm even half the man he is. My dad is gone but I will never forget him."

The other son praised his father as an "avid adventurer, a loving father, family man and a determined and tireless businessman." 

CANADA OPENS INVESTIGATION INTO DEADLY OCEANGATE VOYAGE TO TITANIC RUINS

Portraits of the five crew members of the missing OceanGate Titan sub

Inset, from left: Suleman Dawood, Shahzada Dawood, Stockton Rush; Paul-Henry Nargeolet and Hamish Harding are aboard the OceanGate Titan submersible. (Engro Corp. | Reuters/Shannon Stapleton | @OceanGateExped/Twitter | Felix Kunze/Blue Origin via AP | Ocean Gate/Handout/Anadolu Agency via Getty Images)

"In all of these areas, he constantly sought to be the best man he could be and did nothing half-way. Constantly full of wisdom and life advice to bestow, he made my brother and I into the people we are today. He was an energetic and charismatic man who by the sheer weight of his personality lifted up and supported everyone around him. His tragic loss will be mourned not only by myself and my family but everyone who had the pleasure to meet him. The world is so much less without his larger-than-life presence and his optimistic spirit."

Harding was one of five crew members aboard the Titan sub when it lost contact with its surface vessel, the Polar Prince, around one hour and 45 minutes into its dive Sunday morning, about 900 miles east of Cape Cod, Massachusetts, and around 400 miles southeast of St John's, in Canada's Newfoundland.

CREW KILLED IN ‘CATASTROPHIC IMPLOSION’: TIMELINE OF MISSION TO FIND OCEANGATE'S MISSING TITANIC SUBMARINE

OceanGate tourist submersible

An undated photo shows tourist submersible belongs to OceanGate descents at a sea. Search and rescue operations by US Coast Guard in Boston discovered a debris field identified as the remains of the Titan sub, which imploded after a catastrophic pressure loss.  (Ocean Gate / Handout/Anadolu Agency via Getty Images)

The other passengers were OceanGate CEO Stockton Rush, father-and-son Shahzada and Suleman Dawood, who are members of one of Pakistan’s wealthiest families; and Paul-Henry Nargeolet, a former French navy officer and leading Titanic expert.

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The sub's disappearance led to an international search and rescue effort that lasted for days before authorities found the remains of the sub using a robotic vehicle. 

"The debris is consistent with the catastrophic loss of the pressure chamber. Upon this determination, we immediately notified the families," U.S. Coast Guard Rear Admiral John Mauger told reporters Thursday. "On behalf of the United States Coast Guard and the entire unified command, I offer my deepest condolences to the families."

Fox News' Micahel Ruiz and Bradford Betz contributed to this report.