Rake is the fore-and-aft inclination of the mast from vertical, almost always aft, measured by hanging a weight on the main halyard and reading the distance from the aft face of the mast at the partners or gooseneck to the plumb line. A mast with 150 mm of rake leans aft enough that the halyard hangs 150 mm behind the mast at deck level. Experienced sailors know it as the single rig adjustment that most changes how the boat feels on the helm, because raking the mast aft moves the whole sail plan’s centre of effort aft and adds weather helm, while standing the mast up straighter lightens the helm and, often, costs pointing.
How rake is measured
The blurb definition is the practical method. With the boat on her mooring or in the boat park on a windless day, hoist a heavy shackle or a small weight on the main halyard until it hangs just above the gooseneck. Let it settle, then measure horizontally from the aft face of the mast to the halyard. That distance, quoted in millimetres or inches, is the rake. Some classes convert it to an angle; 150 mm over a 10 m hoist is a little under 1°. Many one-design tuning guides instead quote rake as a masthead-to-transom measurement, taken by hoisting a tape measure on the main halyard and reading the distance to the top of the transom or a mark on the deck. Whatever the method, the important thing is to measure the same way every time so the numbers can be compared.
Rake versus bend
Rake and mast bend are different things and it pays to keep them separate. Rake is the whole mast leaning; bend is the mast curving, usually with the middle bowing forward. Pre-bend is the bend built into the mast at the dock by spreader angle and shroud tension before the backstay is loaded. A sailmaker designs a mainsail’s luff curve to match the bend the mast will have under sail, and designs the rest of the sail to sit in the boat correctly at the rake the tuning guide specifies. Change one without telling the other and the sail will not look as it should.
Why rake matters
The centre of effort of the sail plan sits somewhere in the middle of the sails. The centre of lateral resistance of the hull sits somewhere in the middle of the keel and rudder. The distance between them, the lead, decides how the boat balances. Rake the mast aft and the centre of effort moves aft, closer to or behind the centre of lateral resistance: the boat wants to round up, the helm loads up, and the rudder has to hold an angle to keep her straight. A rudder carrying two to four degrees of weather helm is generating lift to windward and giving the helm feel; much more and it becomes a brake.
Rake also affects pointing. Most boats point higher with more rake, partly because the helm balance lets the boat sail closer to the wind naturally and partly because the geometry of the headsail changes: more rake pulls the headstay aft and flattens the entry of the jib slightly, and the mainsail’s leech moves aft, giving more sail area further back where it helps the boat tack through a smaller angle. Dinghy sailors in many classes rake the mast hard aft in strong winds to depower, and stand it up in light air.
Cruising and racing perspectives
On most keelboats rake is set by headstay length: lengthen the headstay and the masthead moves aft, shorten it and the mast stands up. A cruiser sets rake once, for pleasant helm balance and easy autopilot steering, and leaves it; too much weather helm is tiring, and the cure is to stand the mast up a little. Racers treat rake as a tuning variable. In one-designs a quick-release headstay adjuster or a set of pin positions lets the crew change rake between races for the forecast: more rake for pointing in flat water and moderate breeze, less in light air when the boat needs to be footed, and often more again in a big breeze in dinghies to depower.
Frequently Asked Questions about Rake
Does more rake give more weather helm?
Yes. Raking the mast aft moves the centre of effort aft, which increases weather helm. Standing the mast up reduces it. Aim for a light, positive weather helm of a few degrees of rudder angle.
How do I change the rake on my boat?
On most keelboats, by changing headstay length: a longer headstay lets the mast lean aft, a shorter one stands it up. Re-tension the shrouds afterwards and check the mast is straight side to side.
Is rake the same as mast bend?
No. Rake is the whole mast leaning fore and aft; bend is the mast curving along its length. Both affect sail shape and both should be set to what the sailmaker designed for.
Rake is the rigging adjustment you feel in your hand every time you sail upwind. Measure it, set it to what your sails were designed for, and adjust it in small steps until the boat tells you she is balanced. A rig with the right rake sails herself to windward and makes every sail on board look the way it was drawn.