There are various craft that can be used on inland waterways. Here are a few:
Cruisers come in a variety of lengths and widths and are mainly of GRP (fibreglass) construction.
Narrowboats come in a range of lengths and styles. They are 7' wide and up to 70' long. Normally with engines, they can cruise most of the inland waterway system. Very popular as an 'all round' craft, but the narrow beam does limit space. The hulls of narrow boats are generally made of steel, with the cabins constructed usually of steel, but also of wood or fibreglass. Most narrow boats built in the last 20 years will be of all steel construction. The most common construction size of steel is called 10-6-4. This refers to 10mm Bottom, 6mm to gunwale level and 4mm for the rest.
Some narrow boats may have a more traditional style (called trads) than others. They allow more space in the rear for living accommodation or storage.
Narrow boat cruisers - allow more read deck space. This is useful if several people want to join the helmsman whilst they are steering.
Narrow boat semi-trads - are a compromise between cruisers and trads. They maintain the look of a trad, but with more read deck space, usually for seating and storage.
There are also working boats that carry goods under canvas with a rear cabin. Some of these have also been adapted for pleasure use.
Most boats are built to their individual users' specifications, so you will see a wide-ranging combination of styles, for example longer front decks or portholes instead of windows.
These craft look like narrow boats but are built up to 13' wide and offer much internal space. Practically a beam of 10' to12' is a good maximum to consider. Because they cannot go through narrow locks their cruising area is limited.
There are all sorts of barges, both English and Dutch. Lengths can vary from 40' to 120' plus, with beams from 10' to over 16'. All but the smallest require a reasonable degree of competence to handle them. The larger barges are only suitable for use on major rivers because of their size.
Also common are converted lighters or dumb barges, with no motive power.
Dutch barges are mostly powered, and some are rigged for sail. It is possible to buy unconverted barges either in Holland or in the UK, but the job of conversion is huge, easily under estimated, and is most certainly not for the faint hearted.
These are not powered and not suitable for a lot of moving around, although they can of course be towed. They normally comprise a rectangular steel floating pontoon with a caravan or mobile home type structure built on top.
Many of these types of craft can be used as residential boats.