I imagine since boats floated, people have made them their homes. The fishing communities of China must be among the oldest of liveaboard cultures. These images show the the Causeway Bay Typhoon Shelter in Hong Kong harbor. The first image, from 1976, is from an incredible collection of images by Karsten Petersen. Do not pass up seeing more of his images.
This second photo from panaramio shows the same spot about three decades later. I also found some pictures by Bernard Tse. He describes this community as the “remains of the aboriginal boat people.” In recent images and satellite pictures, it is clear the numbers of people are dwindling from the days off when it appears you could cross the harbor hopping from boat to boat.