Hossain is one of about 800,000 river gypsies, known locally as bedey, who for generations have lived on the nation's waterways between May and December, and on land for the rest of the year.
But now he has decided to give up his nomadic lifestyle because he says the rivers are increasingly erratic and impossible to navigate -- which experts attribute to effects of climate change and upstream development.
For Hossain, who wears only a "lunghi" cloth wrapped around his waist, it means an end of the eight-month season during which he and the families of his four children paddled two rickety bamboo houseboats across the vast delta.
"Many rivers, canals and streams are drying up. We can no longer get to remote areas and without that, we can't make a living," said Hossain, 48, who earns some income diving for jewellery lost by women bathing.
He also catches fish, mainly for his own family's consumption, while his wife and two daughters-in-law are the biggest income earners, selling ornaments and offering herbal treatments for toothache.
Although there is no caste-system in Bangladesh, bedeys are on the bottom rung of society and almost all are illiterate and desperately poor.
They mostly survive by being skilled snake charmers or by selling ornaments, traditional medicine and cosmetics in villages. Some Bangladeshis believe they also have secret healing powers.
But, according to Grambangla Unnayan Committee, a Dhaka-based charity, Bangladesh's bedey community could disappear within a few decades as they abandon their annual migration between land and water.
"The shift to the mainland is happening at a speedy rate. Just 15 years ago, all bedeys were based on water. Pretty soon we may not have any gypsies on our rivers," said A.K.M Maksud, the charity's head.
He said that in the past decade alone 250,000 bedeys had been forced off the water and predicted that within two years 90 percent of gypsies would have to live on land permanently.
Retired history professor Jainal Abedin Khan, who has written books about bedeys, said that they arrived in Bangladesh in the 17th century when the region was part of the Mughal empire.
"They originally hail from what is now Myanmar but they moved across into the delta," he said. "They are a huge part of folklore here, and are the origin of many myths and legends."
Low-lying Bangladesh has one of the world's largest water networks, criss-crossed by 700 rivers, tributaries and canals which cover 24,000 kilometres (15,000 miles) or seven percent of the country's surface.
Bangladesh's Inland Water Transport Authority says that today just 16,000 kilometres of waterways are navigable during the rainy seasons and 6,000 kilometres in the dry months from November to April.
International scientists believe that Bangladesh -- through which the mighty Ganges and Brahmaputra rivers flow into the sea -- is one of the countries worst affected by climate change.
Government river expert Muhammad Imdadul Huq said that increased pollution and changing weather patterns, including unpredictable rains, were the main reasons why rivers were suffering.
"This year we barely had any rain during June. We almost had a drought until heavy rain finally arrived in August. The weather is definitely changing and inconsistent rain -- heavy one month, dry the next -- affects our waterways," Huq said.
Many rivers and streams are also drying up because of human extraction of water, large-scale dumping of industrial waste and unplanned building of hundreds of dams, he added.
Cultural experts say bedeys face many social as well as environmental pressures.
"The ornaments they sell are no longer in demand. Orthodox medicine is preferred so there is no demand for their products," said Habibur Rahman, professor of sociology at Dhaka University.
Rahman added that the gypsies often struggle to blend into mainstream Muslim society.
"Many find it difficult to integrate because they lack education and skills -- and if we lose our bedey people we've lost a slice of our history and culture," he warned.
His sentiments are shared by Soud Khan, 52, a bedey elder who lives with thousands of settled gypsies in Khuria village south of the capital Dhaka.
"All of our predecessors used to live on boats, roaming every place. The boat was our only house as well as our means of transport. We had had better days on boats, but now we are forced to leave them," he said.
"Finding jobs on the mainland is tough. Most of us are not skilled at anything but being bedeys. Of course we want a better life than on the water, but whether we will find it on the mainland, I'm not sure."