George Thomas Wainwright, 32, was diving off the coast of Australia on Saturday when a great white shark attacked and killed him.
Those close to Wainwright say they are shocked this could happen to someone who grew up on the water.
"I can't I just can't believe this happened," friend Grant Ward said.
The shock of losing a friend hasn't entirely hit Ward. What has set in is the heartbreak.
"I was speechless, probably for the first time in my life," he said.
Ward said Wainwright loved adventure and was excited about going to Perth.
He was originally from Florida, but moved to Houston several years ago. Then, he moved from Houston to Australia five months ago on a work visa and started an oil field services company.
Everything in his life seemed to be centered around water.
"He was a charter captain. He ran supply boats here in the gulf, then he went to college [at Texas A&M Galveston] to get his degree in maritime systems engineering," Ward said.
On his final underwater adventure, Australian officials say Wainwright was diving 15 miles from the mainland, off the popular tourist island of Rottnest.
"I talked to him that night. They were actually out there on the island. They had been there, camped, had to get dinner, had a few dives. [He] was going to dive that day then go back to work," Ward said.
Wainwright was in the water by himself. His two friends -- both native Houstonians -- were in the boat when they noticed violent air bubbles, and then a pool of blood.
Minutes later, Wainwright's body rose to the surface. His friends pulled his body from the water, and Australian water police eventually helped get him to shore.
"You never know how any wild animal may react," said George Brandy, aquarium curator at the Houston Zoo.
Brandy said it's possible the shark mistook Wainwright's silhouette against the sun for a sea lion or seal.
"They will cruise along the bottom and they will look up for their food items," Brandy explained.
"I actually dove with him here in the Gulf of Mexico," Ward recalled.
For Ward, whose own confidence in diving is sinking, the devastation is brightened just a little bit knowing his friend died doing what he loved.
"It's just... words can't describe how unfortunate this event was," he said.
Services for Wainwright will be held in Panama City, Florida. His relatives expect his body to arrive in about four days.
Wainwright's death is the area's third recent fatal shark attack. Officials there fear the animal may be responsible for all of them.
A 64-year-old Australian swimmer died two weeks ago and last month, a 21-year-old bodyborder's legs were bitten off by a shark.
Now, crews are employing a controversial method to try to hunt the great white. They're using baited hooks to try to kill it, because, they say, it's threatening to humans.
"My understanding is that they will place some bait away right now within the vicinity where the attack occurred. And if that shark is still in the vicinity, they will try and catch it," Colin Barnett, Western Australia State Premier, said.
Sunday was the first time authorities have exercised the legal exemption to hunt a great white. Scientists say these attacks are unusual, and that Australia averages fewer than two fatal shark attacks a year.
Great white sharks can be found worldwide. Experts say you would only find them in the Gulf of Mexico several hundred miles offshore.