The sister of a Canadian filmmaker who went missing while scuba diving off the Florida Keys says she is “terrified” following his disappearance, but also “hopeful” that he will be found.

Rob Stewart, 37, an award-winning documentarian from Toronto, vanished in the waters near Alligator Reef in the early evening hours of Tuesday.

The U.S. Coast Guard said that the crew of the Pisces reported a diver missing around 5:15 p.m. Tuesday, near Alligator Reef. The diving area is located off Lower Matecumbe Key.

The U.S. Coast Guard said Wednesday that a search involving multiple organizations has been underway since last night, and that search conditions were favourable.

A GoFundMe page has been created to help fundraise for the search for Stewart, who is described in reports as a shark activist. “Coast guard is looking but we need all the help we can get,” the page reads, adding they need “every boat and diver to put all resources into this search.”

Joseph Pickerill, a spokesperson for Canada’s foreign minister, told The Associated Press that he couldn’t confirm personal information, but said that Canadian consular officials “are in direct contact with the family and will support them during this difficult time.”

Stewart’s sister Alexandra, who lives in Toronto, said in a phone interview with CTV News Channel that she is “devastated and terrified but hopeful” as the U.S. Coast Guard and other organizations continue to search the waters for her brother.

“There are divers, airplanes and helicopters out in active search right now, and we’re happy that they’re still searching on the surface of the water,” she said Wednesday afternoon.

According to Alexandra, at the time he vanished, Stewart was on a diving expedition as he worked on his upcoming film “Sharkwater: Extinction,” which is a sequel to his award-winning 2006 documentary.

“It was the third dive of the day, I believe it was just him and another very experienced divemaster but it was a very difficult and technical dive,” Alexandra said. “It was down to 225 feet, which is a depth that is rare even among very experienced divers.”

Alexandra said her brother and the other diver surfaced, but the other diver struggled to get on the boat. The diver collapsed unconscious and began receiving oxygen.

“In that commotion, the boat lost sight of Rob, and they haven’t seen him since then,” Alexandra said.

Alexandra said the dive her brother was performing when he went missing was “quite deep” and her brother was using a sophisticated piece of equipment for it.

“But that said, we were surprised that both he and this other diver suffered any sort of ill-consequences from this dive and it’s hard to speculate about what might have happened there, but diving also has some inherent risk in it, unfortunately.”

Search conditions ‘favourable’

U.S. Coast Guard spokesperson Eric Woodall told CTV News Channel that conditions in the area Wednesday are “pretty favourable.”

On Tuesday night, the U.S. Coast Guard launched a helicopter and sent out a boat crew, which searched all night.

The U.S. Navy, Florida Fish and Wildlife Conservation Commission, the Monroe County Sheriff’s Office and other divers are now also helping with the search.

Woodall said that that the crews will continue to search as long as there is a chance of survival.

Alexandra said she remains hopeful in part because she’s heard that people can survive more than 72 hours in the “nice, warm waters of Florida.”

She said her parents were too devastated to speak, but called on people to help in the search for her brother.

‘Expert diver’

Alexandra said her brother, who began diving at 13, is passionate in his love for oceans, “but really all people and all animals and the environment.” She said he had devoted both his professional and personal life to raising awareness about wildlife and the need for more conservation efforts around the world.

His award-winning “Sharkwater” which examines sharks’ place in the ecosystem, debuted at the Toronto International Film Festival in 2006. The film spurred people around the world to call for bans on shark finning.

Stewart’s other credits include his memoir “Save the Humans” and the documentary “Revolution.”

In an emotional interview with CP24, Ziya Tong, co-host of Discovery Channel’s Daily Planet, called on people to help Stewart, who’s been her friend for nearly a decade.

“I’m very, very concerned,” Tong said on Wednesday. “He’s saved so many sharks and now it’s time for us to save him.”

Tong says that although she’s heartened knowing that Stewart is such an experienced diver, the dive Stewart was on was incredibly challenging. The filmmaker, Tong said, was investigating how shark products are used in the cosmetics industry.

“He was so excited,” Tong said. “I literally got an email from him two days ago... So I’m just very hopeful that we find him and that we bring him home safely.”

With files from The Associated Press and The Canadian Press

ATTN: Boaties of ISLAMORADA Florida, USA If you have a boat with search lights / spotlights, Please help search for Rob Stewart who is lost whilst diving. Details on his FaceBook page. Rob Stewart

Posted by Save Our Sharks on Tuesday, January 31, 2017