People sitting at the bow of boats are at higher risk of vertebral fractures

Nearly 70% of seriously injured passengers in small boats suffer spinal fractures, and most of them sit at the front of the ship, according to a study.

The analysis was undertaken by the Japan Transport Safety Board, a government body that studies the causes of maritime, air and rail accidents.

A JTSB official advises passengers on small boats to move towards the stern where pitching and rolling are less severe, especially in winter when the waves are high.

According to figures from the Ministry of Transport, 2,200 passenger ships operate in Japan, and 70% of them are small ships with a gross tonnage of less than 20 tons.

These small boats are generally used along short sea routes with relatively few passengers.
Although small boats are more susceptible to wave impact, they are not required to be fitted with seat belts. The exemption is designed to allow passengers immediate escape in the event of an accident resulting in the sinking of the vessel.

But that leaves passengers susceptible to falling into their seats on their backs and breaking their spines when high waves rock the boats.

In December 2019, 14 of the 55 passengers aboard the Nankyu, a 19-tonne passenger ship, were injured when it was violently buffeted by high waves off Kagoshima Prefecture. Nine of them fractured their spines when they hit their backs against their seats. All those with fractured spines sat in the first three rows, officials said.

The JTSB studied the 115 passenger boat accidents that resulted in fatalities between 2008 and 2019. Twenty-eight of these accidents involved small vessels and resulted in at least one serious injury each.

A total of 37 people were seriously injured. Twenty-five of them in 16 of the crashes had spinal fractures, accounting for 68 percent of serious injuries.


According to published reports of boating accidents, 28 of the 29 people with severe or minor spinal fractures sat at the bow, officials said.

Passengers in these front seats are at greater risk of spinal fractures because the bow is farther from a ship’s center of gravity, which is closer to the stern, where its engine is installed.

Seats near the bow experience greater rolling and pitching when the ship is buffeted by waves, officials said.

Slower moving vessels are prone to rocking and weaker rocks, so reducing speed when waves are high can prevent injury.

However, four of the accidents that caused vertebral fractures involved boats traveling at relatively low speeds of less than 10 knots (19 km/h).

A JTSB simulation also showed that passengers seated near the bow could be injured by waves 2 meters in height unless the speed dropped to 8 knots.

The COVID-19 pandemic has wreaked havoc on Japan’s passenger boat industry. Many operators saw year-on-year passenger numbers drop by more than half last spring, although the situation improved towards the end of last year.

“High waves are common in winter, so we advise operators to consider reducing the speed of their vessels or even suspending their services,” a JTSB official said. “We also advise passengers to try to take rear seats, if possible, when taking a ride on a small vessel.”

Earnest A. Martinez