Variety and variability
If you have a yen to go coastal cruising in a variable draught yacht that’s less than 30ft long, you’ll need to search in classified adverts or on brokerage listings. Such boats were commonplace in the last century – but sadly there’s precious little now available on the new-boat market apart from the occasional speedy racer, limited production ‘special’ or character gaffer.
Some of the best second-hand options come from French manufacturers. However, it’s important to understand the strengths and weaknesses of the keel-lifting mechanisms that are available. Expect to pay more and incur greater maintenance overheads for high-performance systems that match the windward capabilities of their fixed-keel equivalents, but don't discount the simpler designs that will save you a lot of money and require much less maintenance, unless you are sure you need top upwind performance.
Stability and leeway
A yacht’s stability is determined by its hull shape and the location of its centre of gravity (CG). A broad and flat hull shape will provide plenty of initial stability, but once the force of the wind gets above a certain level, a low CG design will hold more sail and perform better. The lower the CG, the more stable the boat so it follows that shoal (shallow) draught boats tend to have a higher centre of gravity than the fin-keel version of the same boat.
Leeway is also relevant. All boats slide to leeward a bit, but if a boat is not to slide off sideways at speed when it’s on the wind, it needs ‘lateral resistance’. A flat-bottomed boat with nothing sticking out beneath won’t climb to windward. But a fixed plate or keel attached to the underside of the hull can be inconvenient and
