Africans and young children especially are up to 13 times more likely than Western Europeans to become one of the 372,000 people who drown each year, reveal a study by the World Health Organization.
"Efforts to reduce child mortality have brought remarkable gains in recent decades, but they have also revealed otherwise hidden childhood killers," said WHO director Margaret Chan. "Drowning is one."
The UN agency's Global Report on Drowning said most of the children who drown worldwide fall into water during a lapse in supervision. And young children, aged under five, have the highest rates of drowning of any group in the world.
People under the age of 25 accounted for more than half the overall deaths.
Drowning death rates are highest in Africa, and are 10 to 13 times those reported in the United Kingdom and Germany.
People of lower economic status, those who belong to an ethnic minority, lack higher education and live in rural areas all run a higher risk, though there was some variation of results across countries.
The heftiest drowning rates were recorded by low or middle income countries in Africa, Southeast Asia and the Western Pacific, with the last two zones accounting for half the world's drowning deaths.
Children who live near open water are particularly at risk. Ditches, ponds, irrigation canals and swimming pools all provide opportunities for deadly encounters.
People who have to make frequent journeys over water for work or while trying to immigrate using overcrowded, unsafe vessels faced serious risks, as well, the report said.
WHO said local communities could make a dent in the annual drowning toll by providing safe places for children to play and teaching them basic swimming skills.
"Almost all water presents a drowning risk, particularly inside and around our homes," Dr Etienne Krug, a WHO department director said. "Drowning occurs in bathtubs, buckets, ponds, rivers, ditches and pools, as people go about their daily lives."