How long have these houseboats been

How long have these houseboats been here?
Well,they used to build ships here. When the Shipbuilding stopped,there were a lot of leftover materials pieces of wood,glass,and metal. some bohemian kids moved here. They wanted a free lifestyle they didn't have and money,and they didn't want regular job. They lived cheaply by building many of these houseboats out of the junk they found lying around.