houseboat on Ada Ciganlija. United Kingdom In the United Kingdom, houseboats come under various authorities depending on where they are moored. Those that usually do not move from year to year and are in marinas come under local authorities. Those moored on tidal waters (estuaries and coastal harbours) come under various authorities. Most navigable inland waterways in England and Wales come under the authority of either the waterways managed by Environment Agency (EA, sponsored by Department for Environment, Food and Rural Affairs) or the waterways managed by the Canal and River Trust (CRT). Scotland, Northern Ireland and some additional waterways in England and Wales have their own authorities (see List of navigation authorities in the United Kingdom). Both the EA and the CRT distinguish between powered vessels (including sail) and unpowered houseboats. The EA defines Launches as "any mechanically propelled vessel not being used solely as a tug or for the carriage of goods", and houseboats that "includes any pleasure boat which is not a launch and which is decked or otherwise structurally covered in and which is or is capable of being used as a place of habitation". The CRT, which manages 2000 miles of inland waterways, requires any houseboat moored on their waterways to have a "Houseboat Certificate". The CRT define houseboats as "A houseboat is defined as 'a boat whose main use is for a purpose other than navigation and which, if needed for the purpose, has planning permission, for the site where it is moored'. A houseboat may be used for navigation from time to time provided it does not become its main use". The CRT definition provides a very large grey area over what is a houseboat, because an owner of a narrowboat, or other inhabitable vessels (see list of the types of canal craft in the United Kingdom), who live on board, may choose to define their boat either as a cruising vessel (and pay for a cruising licence), or obtain a house boat certificate. It will often depend on which is cheapest, and whether the CRT, or the local authority overseeing a marina's planning permission, allow moorings to be residential (the facilities need meet the requirement of the local authority that allow someone to live permanently aboard at the mooring), or leisure (where the boat can only be inhabited for short periods). The various moorings stretch from Broadness Creek and Benfleet Creek in