Tragic Sinking Delivers Weather Lessons

Controversy continues to swirl about the demise of the 184-foot Perini Navi Bayesian, which sank in August off the coast of Sicily. The 2008 build from the world-renowned Italian shipyard was an award-winning design that had a 237-foot mast and a lifting keel, and that had seemed plenty strong for years, even in rough seas. The sinking was reported globally because among those killed were a British tech tycoon, a prominent attorney and the chairman of Morgan Stanley International.

“Eyewitnesses described furious gales and hurricane-like winds that left an avalanche of debris near the pier,” CNN reported. “More than a dozen survivors were spotted in the area hanging onto life rafts, according to the captain of a nearby boat, who steadied his ship to avoid colliding with the Bayesian.”

Among the many lingering questions in boaters’ minds are: Shouldn’t the Bayesian have been better prepared for the weather? Presumably, on a yacht that size, there was good forecasting equipment on board, and possibly a dedicated weather service.

“The reason that this sinking has gained notoriety is that it was rich people and a really big boat, but it is not all that uncommon,” says Chris Parker of Marine Weather Center, a marine weather forecasting and routing service. “There’s an old saying about the Mediterranean. There’s a reason that the Greeks had ships with small sails and lots of oars. It either doesn’t blow at all, or it blows really, really strong.”

Parker says that, yes, good forecasting would have provided a warning—maybe not for the extreme weather that occurred, but likely for the boat to have been prepared enough to survive it. When the Bayesian went down, Parker says, there was a “pretty strong” low-pressure system over Corsica. It caused significant weather to occur throughout a large area around Italy and the surrounding areas, almost over to Greece.

“The meteorological issues were an unusually high amount of moisture in the water, high levels of precipitable water in the air—generally high moisture levels throughout the atmosphere—and there was a moderately high CAPE index,” he says. “That’s the convective available potential energy, which is an indication of the potential for convective squalls and thunderstorms. The CAPE values were not incredibly high. They were a little over 2,000, which would be enough to cause some concern, but not enough to cause dire warnings.”

There also was wind shear of more than 50 knots, he says, “or wind speed and direction varying over altitude, which sometimes causes tornadoes, waterspouts and microbursts.”

Such an event may have happened because the strongest wind in the mixed layer—the portion of the atmosphere that mixes vertically—was about 60 knots and near 250 millibars. From where the Bayesian was positioned on the water, several miles overhead, there was about 60 knots of wind. “There is always the potential that the maximum wind in the mixed layer will reach the surface,” Parker says.

He suspects a microburst hit Bayesian, not a waterspout, after looking at how much directional wind shear was also present. That’s wind blowing from different directions at different altitudes. “Specifically, are they rotating clockwise or counterclockwise with altitudes,” he says.

When the Bayesian went down, he says, there was almost no directional wind shear. “Freak things can happen, but for high probability of a tornado or waterspout, and for it to be foreseeable beforehand, we would have needed a significant amount of directional wind shear, and there was none that night,” he says. “So, it sounds much more like a microburst.”

A microburst would mean that the 60-knot winds shot downward from several miles overhead to the surface—more straight down, instead of in a rotational way. However, Parker adds: “When the downward rushing air hits the surface, it can’t keep going down. It fans out. It turns into a horizontal wind at the surface. So it’s felt as a horizontal wind, but it’s not air that’s coming from three or four miles away to your left or your right. It’s coming from three or four miles away, above.”

The CAPE index being more than 2,000 would have indicated some risk for vertical motion of air, he says, but likely wouldn’t have been enough to predict such a forceful microburst. “I wasn’t forecasting for this event, but I don’t think I would have foreseen this severe of an event,” Parker says. “I think I would have cautioned vessels to prepare for potentially 40-knot squalls and maybe a few thunderstorms.”

Generally speaking, he adds, that kind of prediction would’ve left the Bayesian at least somewhat prepared for whatever happened. “If they had been prepared for 40-knot squalls, they probably would’ve been OK with whatever they got,” he says. “It would not have been fun, but they would have been more prepared.”

The overall lesson for boaters, he adds, is never to let down your guard when it comes to the possibility of weather changing. “It was a freak weather event, but events similar to this are not all that uncommon,” he says. “Identifying risk factors is important.”

This article was originally published in the November 2024 issue.