Straight answers

It depends on four things: the weight and shape of the hull, how you use the boat (fishing, cruising, sport), the transom height and the maximum power allowed on the builder's plate. An undersized engine never gets on the plane and is always under strain; an oversized one wastes fuel and can stress the structure. Tell us the boat model and length, the usual load and what you expect, and we'll help narrow it down.

A 2-stroke is simpler, lighter and cheaper to maintain, but uses more fuel and is noisier. A 4-stroke is quieter, more efficient and cleaner — the natural choice if you use the boat often — but heavier and costlier to service. Electric motors are silent, need almost no maintenance and suit sheltered waters, rivers and estuaries.

Start with the builder's plate, which shows the minimum and maximum power, and the transom height. Within that range, the choice depends on the weight on board and what you want — reaching the fishing spot quickly or cruising economically. The propeller matters as much as horsepower: often what's missing isn't more power, it's the right propeller.

It matters a lot. Standard shaft lengths are short (S, about 381 mm / 15"), long (L, about 508 mm / 20") and XL (about 635 mm / 25"). Measure the vertical height of the transom. An engine mounted too high loses cooling and causes cavitation; too low makes the bow porpoise, increases consumption and can lead to overheating.

First the diameter, set by the gearbox ratio, then the pitch, which decides whether the boat accelerates faster or carries more load. The goal is for the engine to reach the manufacturer's maximum rev range under normal load. Aluminium propellers are cheaper and bend on impact; stainless steel ones are stiffer and last longer. If the engine doesn't reach its rated revs, the propeller is almost always the cause.

Ask for the service history and real hours of use. Test a cold start, check that cooling water comes out of the tell-tale, look for water in the gear oil and listen for metallic noises at idle. A cylinder-by-cylinder compression test says more than any conversation. Sacrificial anodes should be intact and unpainted.

For tenders and small RIBs, inland fishing and river or estuary boating, absolutely: silent, emission-free, always starts and needs almost no maintenance. The limit is range, which depends on batteries, wind and current. For open sea and long trips, a fuel outboard is still more versatile.

One per person on board, fitted to each person's weight and size. Buoyancy depends on the navigation area: 50N as a buoyancy aid in sheltered waters, 100N for coastal, 150N offshore and 275N for open sea or heavy workwear. We have a dedicated life jackets page with the types available and the questions to ask before buying.

Foam never fails, needs no cartridge and always floats — the best choice for water sports, children and anyone who wants no surprises. Inflatables are more comfortable and discreet but depend on a good cartridge and regular servicing. Many boaters carry foam for everyone and wear an inflatable with harness when fishing or sailing.

It depends on the navigation area, the length and category of the boat, and rules are updated, so always check current legislation before equipping your boat. Generally the list includes life jackets, flares, extinguishers, a bilge pump, navigation lights, a horn, anchor and line, a first-aid kit and a means of communication. Tell us your boat and where you sail and we'll help build the list.

Pyrotechnic flares have an expiry date printed on them — check it twice a year and replace expired ones immediately. Extinguishers need periodic inspection and servicing by a certified company. Don't keep expired equipment: in an inspection, and above all in an accident, responsibility falls on whoever is in charge of the boat.

For many leisure boats it isn't mandatory, but it's well worth it. A fixed VHF with DSC and an MMSI number lets you call the authorities at the touch of a button and be located within minutes, even when your phone has no signal or got wet. For offshore or night sailing, it's probably the best safety investment you can make.

Both, without hesitation. The electric one, with an automatic float switch, handles incoming water without you noticing; the manual one is your backup when the first fails or the battery runs flat. Test both before every trip, keep the intake clean and don't rely on the automatic alone.

Fuel and oil level, battery condition and charge, cooling water, navigation lights, bilge pump operation, life jackets within reach and not stowed away, weather forecast and planned route. Tell someone your plan and approximate return time. Five minutes of routine prevents most breakdowns and scares.