The world has lost one of the giants in speedboating.

George Argyros Jr., 55, suffered a fatal heart attack, bringing shock to the thousands who either knew him personally or admired his devotion to philanthropic efforts, notably the money he donated to causes like the Juvenile Diabetes Research Foundation (JDRF) in conjunction with the Lake Powell Challenge, the poker run he regularly attended.

Argyros was the son of billionaire George Leon Argyros, a former United States ambassador to Spain and the owner of the Seattle Mariners from 1981 to 1989.

George Jr., meanwhile, was president and CEO of Elite Financial Group, the Newport Beach, CA-based company he founded in 2003. Over the years, he owned numerous powerboats—each one for a different “mission,” as he told Speedboat. He was the owner of the famous 43′ Donzi Donzilla vee hull, a classic 1970s Rogers hull, a 39′ Cigarette center console, and a variety of MTIs. Most recently, Speedboat photographed a pair of his newest boats: Chaos, an MTI center console, and Mayhem, a 48′ MTI catamaran.

“We started out with two WaveRunners that we used in Laughlin,” Argyros told Speedboat in 2018. “Then, about 25 years ago, I bought my mid-1970s Rogers, and we ran that boat in Laughlin for 11 years. Eventually, we decided that we wanted to move to Havasu, and bought a single-engine 28′ Tall Deck Eliminator.” By 2010, Argyros decided to buy a bigger boat. He wound up with the 43′ Donzi known as Donzilla.

He built his first Mayhem boat, a 44′ MTI, out of a desire to go even faster on the water. That same need for speed resulted in his trading up to a new Mayhem boat, a 48′ MTI.

Argyros’s passion for supporting charities was legendary. “We kind of focus on children, the elderly, animals and education,” he told Speedboat. “My wife Shannon, me and the Argyros Family Foundation are responsible for giving somewhere between $500,000 and $1 million a year to charity. For example, we’ve donated to the Elephant Cooperation; we gave $350,000 to Child Help; I spent $200,000 at Lake Powell Challenge. And we plan on increasing our charitable donations.”

He was also passionate about flying planes, a hobby he started at age 16. “The first time I went up in an airplane, I was addicted,” he said. “I have thousands of hours of pilot time. I currently fly a Citation jet, a float plane, and a biplane.”

Argyros Jr. is survived by his wife, Shannon Argyros, as well as an 8-year-old son, known as “G3.”