NASIAR KANDI, Bangladesh -- On a hot morning, about 20 fourth-graders sat in two rows of desks, their textbooks open to a Bengali poem called "Song of Palki." One student wrote on the blackboard in the low-roofed room with whitewashed bamboo walls.
This could have been any classroom in rural Bangladesh, except for the sight of an older woman in a sari, bathing in waist-deep water just outside the open window. Sounds of her splashing punctuated the lesson, along with the din of mooing cows and bleating goats. A wooden boat full of passengers and bicycles chugged past.
The classroom was on a wooden boat moored to a riverbank near the village of Nasiar Kandi, Natore District, in northwestern Bangladesh. It is one of 20 free "floating schools" run by Shidhulai Swanirvar Sangstha, a nonprofit organization that has reached almost 70,000 children.
In Bangladesh, annual flooding can disrupt school for hundreds of thousands of students. In some areas, roads are impassable during the rainy season from July to October, when rivers rise as much as 4 meters, or 12 feet. In 1998, the same year Shidhulai was founded, flooding inundated two-thirds of the country, killing 700 people and leaving 21 million homeless.
Bangladesh is a delta formed by the confluence of major rivers and is highly vulnerable to the effects of climate change. More than one million Bangladeshis could be displaced or affected by rising sea levels by 2050, according to the U.N. Intergovernmental Panel on Climate Change, and flooding is likely to worsen in what is one of the world's most densely populated countries, with 152 million people.
"The school on land is closed in monsoon," said Eti Khatum, 9, a student on the boat school, with two long ponytails and a gold-colored shawl. "This school floats all year."
Pascal Villeneuve, the Unicef representative for Bangladesh, wrote in an e-mail, "Making sure that schools are resilient against natural disasters should be a priority for any disaster risk reduction preparedness and planning."
He added, "We know from experience, getting children back into a school environment as soon as possible is the best way to help them recover from the shock and destruction of a natural disaster."
Mohammed Rezwan, Shidhulai's founder and executive director, grew up in the country's northwest, where his organization operates.
His family owned a boat, which meant that he was one of the lucky ones who could attend classes year-round, but some of his childhood friends were prevented from going to school for months at a time because of flooding.
"Many friends and relatives were denied access to education," he said. "I thought, if the children cannot come to school because of floods, then the school should go to them by boat."
He founded Shidhulai with about $500 in 1998, the same year that he graduated with an architecture degree from the Bangladesh University of Engineering and Technology in Dhaka.
Only 22 at the time, he had no experience in fund-raising. But he trawled the Internet for organizations that could help him and submitted proposals. His first boat school was introduced in 2002.
In 2003, Shidhulai received a $5,000 grant from the Global Fund for Children in the United States, and then $100,000 from the Levi's Foundation, part of the clothing company that has factories in Bangladesh.
A $1 million grant from the Bill & Melinda Gates Foundation in 2005 allowed Shidhulai to build more boats, buy computers, install solar power and create a central library. Last year, it added another boat after winning a $20,000 prize from the World Innovation Summit for Education, or WISE, created by the Qatar Foundation.
Mr. Rezwan designed the schools by modifying traditional Bangladeshi wooden boats called noka. They are about 15 meters long and 3 meters wide -- or about 50 feet by 10 feet -- with main cabins that can fit 30 children and a teacher. Weatherproof roofs can withstand heavy monsoon rains and are supported by arched metal beams instead of columns, which would obstruct the classroom. It takes three or four months, plus about $18,000, for local boat builders to refurbish an old vessel. An additional $6,500 a year is needed to pay for salaries, supplies, fuel and other costs.
The organization now has 20 schools -- mostly for the young children of landless families -- 10 libraries and 7 adult education centers, all on boats. There are also five floating health clinics that help transport medical staff to remote areas.
Mr. Rezwan plans to add 100 more boats in the next five years to reach an additional 100,000 people.
"Our floating schools are combination of school bus and school house," he said.
Students board at rural pickup points and then attend classes for two or three hours, six days a week. In many cases, this will be all the education they get.
Free adult classes, meanwhile, focus on practical issues. One afternoon, a room of women in brightly colored saris sat on a boat to watch a slide show by an agricultural expert, who taught them how to use organic insecticides made of neem tree leaves, among other tips.
Khadiza Begum, 27, said that over the past four years, she had learned to grow cucumber and different types of gourds, increasing her crop yields. Without the boat schools, she added, "there is no other way to learn."
Shidhulai employs more than 200 staff members -- including 61 teachers and 48 boat drivers -- and 300 volunteers.
The boat schools are registered with the Education Ministry, which provides free materials for grades three and four. Shidhulai trains the teachers, who are from the local community and usually have a 12th-grade education.
Shidhulai also distributes solar lamps, provides training for growing flood-resistant crops and creates floating gardens and duck coops for landless people.
In a floating library down the river, students checked cricket scores on two computers and perused books from the 1,500 available volumes. The late afternoon light was fading, but solar-powered lights let them continue their work.
Sweetie Khatun, an 11-year-old reading a book called "Rhyme From the Lips of Birds," declared that she loved the library and said that it was "beautiful."world
This article originally appeared in The New York Times.