The deadly inferno aboard a Southern California diving boat has spread grief through the Bay Area’s tightly connected dive community — and a new kind of fear.

Until disaster struck so close to home, safety worries around scuba diving focused mostly on dangerous marine life and occasional undersea accidents caused by malfunctioning equipment or human error, local diving experts said. Now, in the wake of the fire and 34 deaths aboard the commercial diving boat the Conception on Monday, recreational divers in the region are concerned about the vessels that carry them on their expeditions.

“It’s creating this kind of fear of boats now, being on boats,” said Kyle Gorham, an open-water diving instructor at Adventure Sports Unlimited in Santa Cruz. “I’m certainly hoping it’s a momentary thing.”

The passengers who died were sleeping in bunk beds in tight quarters below deck. While the cause of the fire is not known — the National Transportation Safety Board has launched an investigation — the blaze was so intense that both exits from the sleeping area were blocked by flames.

Lafayette’s Marcia Marcellini, who has been diving for more than 20 years and has gone on several trips where sleeping quarters were below the water line, said news of the fire hit her hard. “I was very shocked and very sad. But it’s not just sorrow — it’s fear,” Marcellini said. “It’s a pretty frightening situation. You have to wonder what caused it and how it can be prevented in the future. It kind of scares me, the idea of being below deck on a boat that could light on fire.”

Her dive club, East Bay group Alacosta Divers, has a meeting scheduled for Monday. “We’ll all get together and express our sorrow,” she said, “and certainly offer a moment of silence.”

Though Marcellini believes the diving industry’s safety record is in general excellent, and that the incident will lead to even more focus on safety, she has one immediate concern. “Many of our friends are on a dive boat in Egypt right now,” she said.

The Southern California tragedy left Vallejo resident Linda Pinfold shocked, confused and sad. “Just imagining it is horrific and hard to believe,” said Pinfold, 49, a freelance dive instructor and member of the LGBTQ dive club Northern California Rainbow Divers. “I just want to know what happened and why it happened.”

The incident has given her some trepidation about overnighting on a dive boat, but a finding of the fire’s cause would help combat that feeling, said Pinfold, who has dived from the Conception at least twice. Her greatest concern, she said, is that a new-found fear among recreational divers will lead to fewer people experiencing the undersea wonders off the California coast, where diving helps promote and protect marine ecosystems.

Although worries have arisen among sport divers, industry professionals said they see the fatal fire as a rare exception. But because the nature of diving, especially in this region, forges connections and relationships between people involved in the sport, many divers and pros have been touched by the tragedy and are grieving, Gorham and others in the industry said.

“At this point, the dive community is very shaken. It’s a very close-knit community,” Gorham said. “Everybody knows everybody, especially on the commercial side of it where we’re training recreational divers. Instructors know instructors.

“People are talking to people and a grieving process is definitely starting to happen.”

In the greater Bay Area, from Santa Cruz to Santa Rosa, more than 1,500 people are certified as scuba divers every year, estimated Charles McKinven, senior staff instructor at Pacific Scuba Divers in Sunnyvale. Divers know risks exist, and receive comprehensive training to reduce the dangers of failing gear or human mistakes, McKinven said. Concerns among recreational divers tend to focus on sea creatures, and off the California coast, that means great white sharks, McKinven said. “Now, I think, people are looking at, ‘Is it safe to go on a boat in general?’” he said.

Shortly after the fire on the three-day Channel Islands trip, a couple of people canceled certification classes at Pacific Scuba Divers, McKinven said, but he isn’t certain they pulled out because of the deadly incident. Still, he said, the fact that the fire happened during a dive trip “has a huge impact,” but added, “I would say you’re safer on a dive boat than you are driving on a freeway, on 101.”

Dan King, owner of Diver Dan’s in Santa Clara, said some customers have called with questions and concerns about a trip his company is offering in October on a vessel operated by Truth Aquatics, which also ran the Conception. “We just tell them, ‘Statistically, you’re still really safe — what happened down there was a freak thing,’” King said. However, two people canceled, he said.

Gorham and other dive professionals said the conflagration was especially shocking because of the sterling reputation of Truth Aquatics, which also operates the commercial diving vessels Vision and Truth.

“Truth Aquatics is really an amazingly run operation, and I say that both as a diver and a person who has assisted in leading trips on Vision,” Gorham said. “I’ve never once felt unsafe — some of the most helpful dive crews I’ve ever seen. They’ve run a stellar operation and I would absolutely dive off any of their boats in the future.”

On Wednesday, Pro Scuba Dive Center of Scotts Valley sent a group of divers on a three-day trip to Santa Catalina Island and the Channel Islands. No one canceled because of the Conception fire, but company co-owner Cheryl Babineau said she told her trip leaders to take extra care with the divers because “they’re going to be on edge.”

The fallout of sadness and shock from the fire swept through a network of connections among recreational divers and industry professionals, said Charlie Cooper, owner of Aqua Safaris in Santa Cruz.

“As soon as the word got out about the tragedy, it was all through all of the local diver community on social media. There were a lot of phone calls made and emails made, friends checking up on friends, trying to get an idea of who was on the boat and who wasn’t on the boat, who was safe.”

Diving, Cooper said, is a social sport. “When we teach, we encourage people to join dive clubs,” Cooper said. “People are encouraged to visit their local shops as sort of a community center and resource, not just a place to buy stuff or to take classes.”

For the sport’s practitioners in the Bay Area and Santa Cruz, relationships are fostered by the beauty and challenging cold-water conditions in local diving areas, Cooper said. “That encourages people who dive to meet and know each other and to be stronger divers than people who possibly do all of their diving in the tropics — just the environment encourages a sense of community,” Cooper said.

Now, those in the area who dive or work in the industry are feeling a “heavy sense of sadness,” Cooper said. “The community knew these divers. And the fact that it was such a tragedy and such a huge loss to our community makes it felt very strongly among everyone.”

Gorham said he knew some of the people onboard the Conception and had worked with Worldwide Diving Adventures owner Kristy Finstad of Santa Cruz, who chartered the 75-foot boat and died in the incident. When news of the fire began to spread, Gorham fielded calls about a five-day Channel Islands charter run by his shop that was underway aboard the Vision. Loved ones of those on the Vision trip were trying to find out whether that was the boat that had burned, he said. Once those calls tapered off, grief crept in. “I’m now only starting to feel it myself, and moving into that mode of kind of being able to process what I’m feeling,” Gorham said.

The diving community is feeling the loss up and down the coast. On Thursday evening, hundreds gathered beneath the Santa Monica Pier to honor and mourn the fire victims. In Santa Barbara, a memorial shrine has been set up outside the Truth Aquatics facility in the city’s harbor.

“It’s rattling everyone’s hearts and minds,” said Sara Wilcox, an artist and Santa Barbara resident who was placing artwork she created in honor of the victims at the shrine. Wilcox said she’s been on multi-day snorkeling trips with Truth Aquatics. Those excursions were exciting and beautiful, she said, filled with a sense of camaraderie and awe of the ocean, and left her with “just the best memories.”

Staff writer Annie Sciacca contributed to this report.