NEW YORK — Drowning deaths among boaters in Victoria, Australia, fell from almost 60 in the years before a law required everyone to wear a “personal flotation device” to 16 afterwards, according to a new study.

Educational campaigns encouraging life-jacket use may not be enough to get all boaters to wear the vests at all times, but making it mandatory does make a difference, the study team writes in the journal Injury Prevention.

“Why are life jackets important? Because people don’t float,” Dr. Linda Quan told Reuters Health. Quan, an emergency pediatrician at Seattle Children’s Hospital, was not involved in the study but has examined how changes to the law in Washington state improved life-jacket use.

Washington law requires life jackets to be worn by water skiers and others being towed and by boaters on personal watercraft, or jet skis, as well as by children 12 and under in small vessels.

“What we have shown in Washington state is laws work,” she said, adding that most people wear life jackets now due to the legislation.

“So at least in Washington state people follow the law, and we know if they follow the law they will have less risk of drowning,” she said.

By keeping a wearer afloat after falling off a watercraft, life jackets increase the person’s chances of being rescued, according to Lyndal Bugeja of the Coroners Court of Victoria, who led the new study, and her coauthors.

“This study showed a highly significant reduction in drowning deaths following the introduction of compulsory PFD wearing regulation in Victoria in late 2005, heavily influenced by the significant decrease in drowning deaths among occupants of small powerboats,” the authors write.

Before December 1, 2005, Victoria law required boats to carry life jackets for each person onboard, but only children under the age of 10 and water-skiers had to wear them.

The new law implemented at the end of that year requires all occupants of small boats wear life jackets while the boats are in the water. Passengers in larger boats must wear them at times of heightened risk, such as nighttime or when the driver is the only person on the vessel.

Bugeja and colleagues wanted to examine the impact of these laws so they compared coroners’ records from a six-year period before the regulations went into force, when there were 59 recreational boating drowning deaths, to the five years afterward, when there were 16.

The largest decreases in deaths were seen among people under age 60 and those who were pleasure cruising. No significant change was seen among people fishing.

The researchers also discovered that 11 of the 59 people who drowned before 2005 were wearing life jackets, but two had them on incorrectly and two more had the wrong kind.

In the period after the law took effect, five of the 16 people who drowned were wearing acceptable personal flotation devices, but two of the 16 had the wrong kind and one was worn incorrectly.

“These findings provide further support for the adoption of a regulatory approach, supported by visible promotion and enforcement, to increase PFD wearing in other jurisdictions,” the authors conclude.

The study team acknowledges that other factors may also have affected the number of drownings after the law went into effect. During that period, for example, more boats carried radios and mobile phones, plus alcohol use by boaters declined.

In the U.S., federal law mandates that boats carry life jackets for all passengers, but it does not require that they be worn. All states have regulations about life-jacket use by children, although the requirements vary by age.

Quan believes that most drownings are preventable. But she said consumers need to be careful about how they choose life jackets.

“The only life jackets that people should use are ones that are U.S. Coast Guard approved,” she said.

Quan added that parents need to know how much their children weigh and then the life jackets need to be worn correctly.

“You have to know how to put them on — that means you buckle up everything,” she said.

Quan added that it’s also important for adults to wear life jackets, both to avoid drowning themselves and to set an example.

“If an adult is wearing a life jacket in the boat it’s much more likely that the kids — even a teenager — is going to be wearing a life jacket,” she said. “In other words, role-modeling helps.”