Susana Solano Rosas identified three of her daughters and their father — Evanmichel Solano Quitasol, Nicole Storm Quitasol, Angela Rose Quitasol and Michel Storm Quitasol — as some of the passengers who were part of the diving excursion aboard the 75-foot commercial vessel called the Conception.
Her daughters' stepmother, Fernisa Sison, was also on the boat, according to Rosas.
"The authorities do not have much to say to us," Rosas said on Facebook Tuesday. "Thank you to all of you for your support prayers and good wishes."
Kaiser Permanente Central Valley also confirmed that Fernisa Sison, Michael Quitasol, and Evan Quitasol were among those presumed dead.
"Our sympathies are with their family and friends at this time," Corwin Harper, senior vice president and Area Manager said in a statement. "We are providing support to those at Kaiser Permanente who are affected by this loss."
Pacific Collegiate School, a charter school located in Santa Cruz, said that two of its students aboard the Conception with family members. The school identified students Berenice Felipe, Tia Salika and Salika's parents as four people on board, in a letter addressed to the Pacific Collegiate School community.
"While this was not a school sponsored trip, our hearts and thoughts are with the families of the victims and those yet missing, particularly those of our students and parents on board," the school said in a separate statement posted to its website.
The mother of Allie Kurtz, 25, confirmed to NBC News that her daughter was on the trip and is presumed dead. Kurtz loved diving and "was following her dream," her mother said.
Let our news meet your inbox. The news and stories that matters, delivered weekday mornings.
Dignity Health, a healthcare company based in California, released a statement Tuesday that said a nurse and two former staff members were on the vessel but did not release their names.
"Our hearts go out to all the families and loved ones of those on board the Conception," the company said. "Out of immense respect for the family’s privacy, we do not have any other words to share at this time.”
Heather Sawdon said in a statement that her sister, Kristy Finstad, a marine biologist who co-owned Worldwide Diving Adventures, was among those presumed dead.
"Marine Biologist Kristy brings her microscope to show divers silicious spicules and pumping pedicellariae — the colors on marine invertebrates are amazing up close!" said a description of the doomed three-day trip from Truth Aquatics, which operated the boat out of Santa Barbara.
"My mission is to inspire appreciation for our underwater world," Finstad wrote on her company's website.
Finstad, 41, studied damselfish and corals in the Tahitian Islands, dove for black pearls in the French Polynesian Tuamotus Islands and counted salmonids for the city of Santa Cruz, where she lived. She also did research for the Australian Institute of Marine Science and wrote a restoration guidebook for the California Coastal Commission.
She and her husband had just returned from sailing across the South Pacific.
“She’s extremely strong-willed and very adventurous,” her brother, Brett Harmeling, told the Los Angeles Times. “If there was a one percent chance of her making it, she would have made it.”
The U.S. Coast Guard has not released identities for any of the 20 victims recovered from the water. Officials said Tuesday that crews were trying to get to recover between four and six additional bodies that were seen trapped within the wreckage of the boat.
Five of six crew members, who were on the third deck of the ship when the fire broke out, jumped off and were rescued by a "good Samaritan" recreational vessel, according to U.S. Coast Guard Capt. Monica Rochester. She said Tuesday that the crew's quarters are on the top deck, so it was "perfectly normal" for them to be there.
It's unclear if the victims woke up and tried to escape the flames, or perished in their sleep, Rochester said.
The Conception was in full compliance with regulatory requirements, Rochester said Monday. The Coast Guard inspects vessels like the Conception annually.
The boat was on a three-day $665 diving excursion "to explore the pinnacles of San Miguel Island," according to a Truth Aquatics schedule. It departed Saturday morning and was due back Monday evening.
Truth Aquatics is a Santa Barbara Harbor-based operation that has been in existence since 1974.
Bob Hansen told NBC News that he and his wife were in their boat, "The Grape Escape," in a cove about 400 yards away at the time of the fire and helped the captain and four crew members who managed to escape.
Hansen said one of the crewmen had what appeared to be a broken leg, and another said his girlfriend was on board and did not make it off, Hansen said. They were clearly distraught, with some crying, he said.
“They felt so helpless. They said that with everything — so much on fire so much that they just couldn't get to them,” Hansen said.
CORRECTION (Sept. 5, 2019, 9:22 a.m. ET): An earlier version of this article misspelled the name of one of the students who died on board. Her name is Tia Salika, not Salinka.
Doha Madani is a breaking news reporter for NBC News.