In a construction such as houseboat the head element is boat, and can therefore be viewed as the hypernym.
The houseboat dweller must produce his certificate, his licence to exist, on demand and there is a fine of £2 per offence for not doing so.
At least 12,000 people—probably a good many more—live on houseboats, so we are dnot dealing with a tiny section of the population.
Similarly, although there are 169 authorised houseboats, we know that there are another 1,000 that are unauthorized—a serious problem.
I turn now to those who live in caravans or houseboats.
After all, one cannot move one's house, but if a houseboat is sound it ought to be movable.
Does it mean a raft, yacht, houseboat, barge or ark?
For example, small yachts may go a long way out to sea, yet many of them are used as houseboats.
