But Julie Munger, owner of Sierra Rescue, a Taylorsville, Calif., swift water and flood rescue company, said warm waters were irrelevant unless they were comparable to the body's temperature of 98.6 degrees.
"Eventually, if the water temperature is lower than the body temperature, you can succumb to hypothermia," she said. "It wears you down over time."
The biggest determinant of survival in a boating accident is using a life jacket, according to Munger.
"I have been around water for 30 years," she said. "I've seen friends drown in lakes paddling on flat water. It's an important warning to use life jackets and then your chance of survival increases."
And for those who are on cruise ships or sleeping, "know where the life jackets are so you can grab one," said Munger. "A lot of people don't pay attention to the briefings."
Baja survivor David Levine said that when the boat capsized, the men ran to the deck to help each other. "Everybody jumped into the water," he told the San Francisco Chronicle. "A lot of people went in with no life vest."
Joelle Bautista told the newspaper that her husband Russell Bautista, who is still missing, grabbed a life jacket but, "from what I heard, it was hard to hold on to them if you were running."
Those who did survive were shown in photos Monday in T-shirts and Bermuda shorts waiting to board buses. All were in good condition -- some with sunburns -- and with a few scrapes.
They had paid $995 per person for the six-day charter. The tourists, most from Northern California, had spent the night before eating gourmet dinners of fresh-caught fish.
The accident happened on their second day, about 60 miles south of the Port of San Felipe, a haven for windsurfers and sports fishermen.
Tourist Michael Ng of Belmont, Calif., said that he and another fisherman made it to shore buoyed by an ice chest.
"I'm relieved I'm alive, but I'm scared for the people who haven't been found yet," he told the Mercury News. "We were not very far from shore, so people were beached or stranded on some local islands."
Ng, an avid fisherman, went on the all-male trip last year and had bragged to his wife about coming home with "monster" fish. This trip "was supposed to be another great story," said Ya Ng.
But the families of the seven men who are still unaccounted for worry they might not get to recount those tall tales.
"I'm beyond concerned," Kristina Bronstein, who is engaged to missing tourist Mark Dorland of Twain Harte, Calif., told the Associated Press.
Dorland, 62, was one of the first people to fall into the water, according to the Associated Press. He wasn't wearing a life vest.
His survival may also depend upon whether he was isolated or with a group of other survivors, as it's harder for rescue teams to find a lone survivor.
"With someone else to commiserate with, that can buoy spirits," said McGinnis. "If it's a large group it's easier to spot, but it's still a big ocean."