There are at least 3,000 miles of waterways in Britain.On these canals and rivers,there are over 30,000"houseboats"-boats that people use as homes.Around 10,000 of them are located in London.The earliest populations of Britain's"boat people"have been living on the water since thecanals were built in the industrial revolution.Since then,houseboat living has usually attracted people who prefer to live an altemative ifestyle.