How to read a boat spec sheet like a pro

A well-read spec sheet tells a boat's story more honestly than any brochure: who it is for, how it will behave, what it will cost to keep. You just need to know which numbers to look at, which to compare — and which to ignore. Here is the method we apply to every Yachture entry.

The lengths: three figures, three uses

Length overall (LOA) includes bowsprit and pushpits: it is what marinas bill — nowadays to the centimetre. Hull length, shorter, appears on the registration papers and drives certain regulations. Waterline length, finally, governs the speed of a displacement hull: the longer it is, the faster and more seakindly the boat. A "45-footer" can measure 13.4 or 14.6 metres overall depending on the brand: always compare like for like — our comparator does it line by line.

Displacement, ballast and what they promise

Displacement — the boat's mass — must be read in context. Heavy (for its length), the boat will be gentle in a seaway and happy to carry cruising loads, but slower and thirstier; light, it will be lively and quick, but harsher in a chop and sensitive to overloading. On sailboats, the ballast ratio (ballast/displacement, typically 30-40%) hints at stiffness under sail; a deep keel stiffens more efficiently than a heavy, shallow one. Each of these terms is defined in plain words in our glossary.

Engines: power, speeds and consumption

Power alone means nothing: 2 × 440 hp drives one 15-metre flybridge at 28 knots but barely 20 on a heavier hull. Look instead at the cruise/top speed pair: a narrow gap (23/26 knots) signals a boat run close to its limit; a wide one (9/24) betrays a dual-mode semi-displacement hull. Fuel capacity, crossed with consumption (rarely published, alas), gives the real range — the number that decides a safe passage.

Capacities and accommodation: the hidden brief

Water, fuel, cabins, berths: these figures reveal the yard's intent. 300 litres of water on a 45-footer? A boat designed for coastal hops and marinas. 800 litres with a watermaker option? Bluewater cruising. The mention "3 – 4 cabins" flags an owner/charter platform — the 4-cabin version feeds charter fleets, which matters at resale time as we explain in buying ex-charter.

CE category, architect and vintage

The CE design category — A (ocean), B (offshore), C (inshore), D (sheltered) — describes the conditions the boat was designed for, with a maximum crew per category. It replaces neither the mandatory safety equipment nor your weather judgement. The architect's name (VPLP, Berret-Racoupeau, Olesinski…) tells you a hull's lineage; the year and generation, the deck-plan evolutions: the same model name can hide two very different boats ten years apart.

The numbers that are missing

A spec sheet also reads through its absences. Fuel burn at cruising speed, the real loaded weight (published displacement is usually the light ship — no water, fuel or gear), headroom or air draft regularly go missing. Two reflexes: ask the yard or broker for the manufacturer's consumption curves, and mentally deduct 10-15% from published speeds — measured on a new boat with a clean hull, flat water and half tanks. A seller who hands over those figures without being pressed is also telling you something about his transparency. And when two rivals publish figures measured differently, only a sea trial settles the argument.

Where to start

Take the sheet of a model you fancy and those of its two direct rivals, and line them up: LOA, beam, displacement, capacities, cabins, CE category, power and speeds. The gaps leap out and tell three different design philosophies. That is exactly the exercise our files enable — and the best training before walking a boat show or booking a sea trial.