Start with the hull

Nearly every narrowboat on the UK network has a steel hull, and the condition of that steel matters far more than the colour of the kitchen cabinets. When you look at a boat, ask for the baseplate thickness and the thickness of the hull sides. A well-built modern shell will typically have a 10mm baseplate and 6mm sides; older boats may be 6mm and 4mm respectively. Thinner steel is not automatically a problem, but it gives you less metal to lose to corrosion before expensive overplating becomes necessary.

Steel hulls are protected by blacking — a bituminous or epoxy coating applied below the waterline — and by sacrificial anodes welded to the hull. Blacking usually needs renewing every two to four years. Epoxy is more expensive but lasts longer, often seven to ten years, and is a genuine plus point when you find it on a boat's history. Ask when the boat was last out of the water, what was done, and whether there are photographs.

You will also see glass-reinforced plastic (GRP) cruisers, and the occasional aluminium hull. GRP is common on rivers and suits gentle inland cruising, but it is not really a narrowboat, and it fares poorly against lock walls and submerged shopping trolleys. Aluminium is light and rust-free but rare, expensive and harder to repair in a traditional boatyard.

Stern styles: traditional, semi-traditional and cruiser

The stern is where you stand to steer, and the three classic layouts each suit a different sort of boater.

• Traditional stern: a small rear deck with a sliding hatch, the steerer standing in a narrow space partly enclosed by the cabin. It is warm, secure and weatherproof, but sociable it is not — you cannot easily chat with crew behind you.
• Semi-traditional: the same profile with a wider rear deck and often a set of rear doors into the boat. A good compromise, and by far the most popular choice for first-time buyers.
• Cruiser stern: a large open rear deck with railings and bench seating, sometimes with a pram cover. Brilliant for entertaining and for guests, but the deck fills with rainwater and leaves, and the steerer is more exposed in winter.

If you plan to cruise through the winter, or to live aboard, the semi-trad or traditional stern is usually the kinder choice. If you want friends aboard for summer evenings on the Grand Union, a cruiser stern earns its keep.

Length, layout and the 57-foot question

Most first boats fall between 40 and 60 feet. Length buys you living space, but it also limits where you can go. The Leeds and Liverpool, the Calder and Hebble and the Chesterfield all have short locks, and anything over about 57 feet will struggle on parts of those routes. If you dream of the full network, a boat of 55 to 57 feet is the pragmatic sweet spot. If you will mostly cruise the Grand Union, Oxford and Kennet and Avon, a 60 to 70-footer gives you a proper bedroom, a walk-through bathroom and a decent saloon.

Layout matters as much as length. The traditional arrangement puts the bedroom at the front and the saloon at the back; a reverse layout flips this, so the galley sits near the stern and the bedroom is furthest from engine noise. Walk through a few boats before you decide. Pay attention to bed size — many fixed doubles are only 4 feet wide, which is snug for two adults — and to whether the bathroom is a walk-through or a separate room with a door. For a liveaboard, storage is the real currency: look for cupboards, a proper wardrobe and somewhere to put a bicycle, a coal scuttle and a water hose.

What your budget actually buys

Prices have risen sharply in recent years, but as a rough guide for the 2020s market:

• Under £25,000: a project boat or an older shell. Expect to spend again on hull work, electrics and heating. Fine if you enjoy restoring, risky if you do not.
• £30,000 to £55,000: a solid, tidy boat of 1980s to early 2000s vintage, often with a reputable engine and a recent survey. This is where most sensible first purchases sit.
• £55,000 to £90,000: a well-presented boat with modern electrics, a multi-fuel stove, solar panels and a decent inverter. Often fit for year-round living.
• Over £90,000: near-new shells, high-spec fit-outs and bespoke builds.

Engines are usually marinised diesels — BMC, Beta, Isuzu, Lister and similar — and most are reliable if serviced. Ask for the engine hours, when the oil and filters were last changed, and whether there is a spare set of belts aboard.

The costs that catch first-time buyers out

The purchase price is only the beginning. Budget for the following each year:

• Canal and River Trust licence: typically £1,000 to £1,500 for a 50 to 60 foot boat, depending on length and prompt-payment discount.
• Moorings: from around £2,000 for a rural offline berth to £6,000 or more in a popular marina near a town. Continuous cruisers pay nothing for a mooring but must genuinely move every 14 days.
• Insurance: roughly £250 to £500 a year for a narrowboat, more for liveaboard cover.
• Boat Safety Scheme certificate: required every four years, around £150 to £200 plus any remedial work.
• Maintenance: blacking, anodes, engine servicing and the inevitable pump or alternator. Set aside £1,000 to £2,000 a year.

Rivers, estuaries and the survey you must not skip

If your cruising will include rivers such as the Thames, the Severn or the Trent, you need more than a canal boat. Tidal sections demand a decent anchor, a VHF radio, a reliable engine and, ideally, a Boat Safety Scheme certificate plus suitable insurance for the waterway. Tell your insurer exactly where you intend to go.

Whatever you buy, commission an independent pre-purchase survey before you hand over money. Insist on an out-of-water survey with ultrasonic thickness readings taken along the hull, not just a quick glance from the bank. A survey costs a few hundred pounds and regularly saves buyers five figures. No survey, no purchase — that single rule will serve you better than any other advice in this article.