She May Have Already Been Sinking Before Anyone Noticed

Marine Trader 50 Could Easily Handle 20 People. A Burst Hose, Not So Much

Peter Swanson Jul 16

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No, the Marine Trader that sank off Alcatraz was not overloaded with people. According to our go-to-expert on marine disasters, the 50-footer had almost surely been sinking long before anyone noticed. Then, at the critical point, she went under too quickly for anyone to make a Mayday call.

Of 20 on board, three people were lost in Tuesday’s sinking, plus a dog. Volare had been on a mission to scatter the ashes of a friend—a quick out-to-sea and back. This type of trawler yacht may not have been an ocean-crosser, but she was designed to easily handle normal sea conditions in San Francisco Bay, reported as four- to five-foot seas and Force 4-5 winds that day.

Roger Long is a retired naval architect who specialized in designing research vessels and sailing ships. He has testified in official proceedings about vessel stability in connection with disasters at sea. He helped Loose Cannon readers understand the sinkings of Bayesian and Pride of Baltimore.

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Moreover, Long cruises the East Coast in a Gulfstar 43, a trawler of similar vintage and design as Volare.

Regular news accounts are rarely very helpful when the marine community is trying to figure out why a perfectly good boat decided to capsize or sink. Getting “slammed” by a five-foot wave, as the San Francisco Examiner reported, would not have been enough. John Arndt framed the real question, writing in the July 15 Latitude 38 online marine news outlet:

While many news reports did mention rough seas, they certainly weren’t any rougher than most sailors, wingfoilers and other boaters regularly experience while sailing San Francisco Bay. We are experiencing king tides, which could account for some additional chop, but realistically, it feels as if something unusual happened to cause this tragic accident. These were “normal” Bay conditions, so some other explanation is probably needed to understand why a solidly built 50-ft trawler somehow faltered on the Bay.

Long is fairly certain the explanation is “undetected engine room flooding.”

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The Coast Guard reported that the boat was hit by a wave, causing it to suddenly capsize and throw people into the bay. Yet the images of the Bimini top just peeking over the water show Volare awash but upright. Then she sank.

According to Long, who has done the math, no matter how people on board were distributed during the reported sea conditions, their weight would not topple Volare onto her side, let alone sufficiently to submerge the boat’s engine intake vents.

Long said similar designs are licensed by the Coast Guard to carry up to 49 passengers.

An unusual design feature of the Marine Trader 50 is that each of her twin engines has its own stand-up engine compartment, separated by a corridor that leads from the main accommodations area to an aft cabin.

Long noted that a diesel engine will continue to run until water rises high enough to flood its air intake. In other words, a lot of water can come in before a stalled engine makes the problem apparent. According to Long, a possible culprit in the flooding was a burst raw-water cooling hose.

If the doors to the engine compartments were all closed, water coming into one side might create an asymmetrical flooding scenario, at least initially (and depending on how well the doors were sealed).

Retired Coast Guard Lt. Commander John Mixon, speaking to NBC News, speculated that the seeming rapidity of Volare’s sinking may have been due to “water intrusion in the lower levels of the boat.”

The vessel was barely two miles from getting back to her embarkation point at San Francisco when the accident happened, and the number of people and the social nature of the outing may have masked the fact that the boat was beginning to handle poorly, Long said.

A broker who once helped sell Volare was very familiar with her. After the disaster, he spoke to a witness. “I believe it was a mechanical failure in the port engine room, which was sealed. But the facts will come out,” Mike Garner said in a Facebook comment. “I say that because one of my close friends, who is a captain, was there and witnessed this tragic incident from the beginning to the end. What he described to me made sense.”

According to news accounts, the Coast Guard will investigate the feasibility of recovering Volare, which now sits on the bottom 128 feet down. Some number of the missing three bodies may be inside her.