James Smith, a veteran sailor and captain of the fishing vessel California Dawn, was sailing his boat under the Golden Gate Bridge on Tuesday when he heard the call on his radio: A ship was in distress near Alcatraz Island.
From a distance, Smith saw what looked like steam or smoke rising from a speck in the water. As he hurried to the scene, he saw that a large motor vessel was rapidly sinking. Some passengers clung frantically to the hull of the partially submerged ship, he said, as rescuers administered CPR to a man on a San Francisco police boat.
“Something went catastrophically wrong with the boat for it to sink like that,” said Smith, who has operated charter boats for 35 years. “It wasn't just because a wave hit him and he just flipped over.”
Rescuers rushed to get 17 people to safety, but after reaching shore, the man who was given CPR was pronounced dead. On Thursday, a female passenger was recovered from the bay and pronounced dead. Two passengers are still missing.
A California Highway Patrol helicopter flies near the base of the Golden Gate Bridge as search and rescue operations continue after a Tuesday boat sank Wednesday in Sausalito, California.
(Noah Berger/Associated Press)
As search teams continued to scour the bay Thursday to find the missing passengers and recover the wreckage of the sunken ship, it remains unclear what caused the 49-foot, three-level vessel to roll on its side and fall into the water.
According to Capt. Jarod Toczko, commander of the U.S. Coast Guard's San Francisco Sector, survivors of the incident reported that a wave hit the ship, causing it to list heavily and suddenly capsize.
But maritime investigators and experts, including the captain who was in the bay that day, told the Times that it was unlikely that a single wave would cause such a large cabin cruiser to sink. While the exact cause will not be determined until officials recover the ship from the ocean floor and conduct a full investigation, they said the ship, which was carrying 20 passengers at a memorial honoring a loved one, likely took on water after a series of problems or cascading failures.
Although the water was rough Tuesday afternoon, Smith said, it was not extremely rough. He estimated there was maybe a 4-foot wind gust and said the smaller boats on the water did well. Under such conditions, a 49-foot boat would normally be stable and would not be expected to be overloaded by 20 passengers.
This particular ship, he noted, had already ventured into rougher waters earlier in the day, passing under the Golden Gate Bridge into the Pacific Ocean before returning across San Francisco Bay toward Angel Island, before returning to the more sheltered waters of the bay.
Several factors, Smith said, could have caused the boat to take on water as it headed back to a San Francisco marina. The ship, called Volare, could have lost the water line that cools the engines, he said, or lost the metal shaft that transfers rotational power from the engine to the propeller to propel the ship forward.
“I guess you lost a cooling line,” Smith said, referring to the raw water line that pumps water to cool the engine and sends it back to the back of the boat. That, he said, could explain the steam coming off the ship. On a boat that size, he said, the line would probably be 1½ to 2 inches thick.
“A 2-inch hole in your boat doesn't take long to start filling up,” Smith said. “You're on a cruise ship, there are a lot of people, a lot of noise, maybe the ship rocks and you don't even realize it before it's too late.”
With Alcatraz Island in the background, flowers float in San Francisco Bay as search and rescue operations continue for missing victims of a ship that sank Tuesday in San Francisco.
(Noah Berger/Associated Press)
Randell Sharpe, a Bay Area marine accident investigator, agreed that a wave probably did not cause the ship to sink. Most likely, he said, there were multiple aggravating factors.
“For a boat that size to be basically overtaken, it's not going to be just a single wave,” Sharpe said, noting that photos and videos from the scene showed the water was rough, but not strong enough to capsize a large motor boat.
The waves could have caused the boat to rock back and forth, Sharpe said. But even then there would have to be openings (in the portholes or in the sides of the lower cabins or some flaw in the engine room) that would allow too much water in and cause the ship to lose stability so quickly.
A photograph of the ship, he said, shows seven windows along the side below the main deck. If the windows were open, he said, the ship could have suddenly taken in an enormous amount of water once it started rocking.
“Were the windows open?” Sharpe said. “Do you find any other source of leak in the engine room, possibly a hose going to one of the engines, or just a drain hose, or something that allowed water to come in from below the waterline?”
If there were a problem, he said, the distribution of passengers on the ship could exacerbate the problem: Too many people on top would make the ship heavier.
According to survivors, Toczko said, some passengers were below deck, but many were on the main deck when she ran into trouble.
“Were you all standing on the same side of the ship, facing the front of the city?” Sharpe said. “That would worsen the stability of the ship, so it tends to lean more in that direction.”
After looking at the ship's tracking data, Capt. Jim Elfers, a marine surveyor in the Bay Area who performs damage inspections and safety assessments of yachts, said that when the ship left Ayala Cove on Angel Island, heading back toward the front of town, it could have been the victim of a cascading effect called the “sea beam effect.”
“It's a cyclic roll that sets in when a boat takes even a 4-foot wave cyclically over and over on the beam,” Elfers said, referring to the widest point of a boat's hull. “A roll is created and, in this case, the center of gravity of this boat may have become very high. If you have [20] Passengers on a 50-foot boat, especially if they are on the upper deck, have their center of gravity high up. “The ship enters a cyclical movement.”
If a large wave managed to reach the decks, which is not unusual in San Francisco Bay, Elfers said, that could present problems if the ship were not watertight: Water would find its way to any small compromised area or any place that is not sealed and enter the hold and start a cascade of negative effects that could make the ship less stable and slightly lower in the water.
“And the next wave comes, the next wave comes, and suddenly you're capsizing,” Elfers said. “It's like when you have a child on a swing, you can push him with two fingers slowly, but slowly you can get to the point where you are actually moving on that swing.”
After being a licensed captain for 35 years, Elfers said he was always careful, if he started to notice a beam sea effect and had a lot of passengers aloft, to lower people into the cockpit.
“Normally you would get a little warning, because the ship is starting to rock, but it hasn't gotten terrible yet,” he said. “That's the time when you're trying to move people around and get the weight down. I personally would have said, 'Hey, look, this is going to get a little shaky for the next 20 minutes. I need half of you, or all of you, to go lower in the boat.'”
Elfers also said it was very common for a boat engine, which does not have a closed cooling system like a car's, to have a hose that ruptured or a hose clamp that failed.
“Something goes wrong and the engine starts pumping water into the engine compartment,” he said. “That's very common because the engine constantly draws in from the ocean to cool it.”
It is unclear how thoroughly the ship, which was documented in Stockton, was maintained or inspected prior to this week's voyage.
According to the San Francisco Chronicle, John Boisa, 62, owned and captained the ship. He was the younger brother of Clifford Joseph Boisa, the passenger who died in the incident. A family member told media that his brother was an experienced sailor.
“He was a Navy officer and he knows how to handle a ship,” his brother, Ralph Boisa, told CBS News. “It's been to the bay, through the Golden Gate and up the coast many times without any mishap whatsoever.”
Smith said he could only guess about the boat's maintenance or the captain's experience, noting that it was a private boat.
“I hate to speculate because ships can sink at any time,” Smith said, noting that “all kinds of weird things” had happened to him in his 35 years at sea. “Some kind of coincidence could have happened.”
People should always be careful when in the water, Sharpe said.
“You have to perform regular and constant maintenance on a boat,” he said. “It's not a car you can take in every six months or once a year for an oil change.”
“Until the Coast Guard lifts the boat or they do some other preliminary investigation, no one knows.”
On Thursday, divers from the San Francisco Police Department's Marine Unit, in close coordination with the U.S. Coast Guard and other partners, conducted a networked search for the vessel, believed to be about 120 feet deep on a rocky ocean floor, using boat-mounted sonar platforms and other tools.
Once the ship has been located and positively identified, the department said in a statement, it will coordinate with the U.S. Coast Guard and other partners to evaluate recovery options and determine if it can be recovered from the ocean floor.
