2 min read · Updated 22 June 2026
The main parts of a sailboat are the hull, the keel, the rudder, the mast and rigging, the boom, and the sails. Learn these half-dozen and you can describe and understand almost any sailboat. Here is what each does, working from the body of the boat outward.
The hull
The hull is the body of the boat — the part that floats and carries everything else. Its front is the bow, its back the stern, and its width is the beam. Standing on board facing forward, the left side is port and the right side is starboard — terms used because they never change with which way you face, unlike left and right (see port and starboard). The shape of the hull governs much of how a boat performs, as yacht hull design explains.
The keel and rudder
Underneath the hull are two fins:
- The keel — a fin, usually weighted with ballast, that does two jobs: its weight keeps the boat upright, and its shape stops the boat slipping sideways, which is what makes sailing upwind possible. A keelboat is defined by having one; dinghies use a lighter, liftable centreboard instead.
- The rudder — a steerable blade at the back, turned by a tiller or wheel, that steers the boat.
The mast, boom and rigging
Above deck, the mast is the tall vertical spar that holds the sails up, and the boom is the horizontal spar along the bottom of the mainsail — the one to keep your head clear of, since it swings across when the boat turns. Holding it all together is the rigging, which comes in two kinds:
- Standing rigging — the fixed wires or rods that hold the mast up: the forestay (front), backstay (rear) and shrouds (sides).
- Running rigging — the ropes that move: halyards raise the sails, and sheets control their angle to the wind.
How many masts and sails a boat carries is its rig.
The sails
Most boats fly two sails: the mainsail, set behind the mast, and a headsail (a jib or genoa) in front of it. Downwind, a boat may add a big, light spinnaker — see what is a spinnaker. The sails are what capture the wind and drive the boat, working as wings, as how do sails work describes.
Deck and cockpit
Finally, the crew works from the deck and the cockpit (the recessed area where the helm and controls are), using winches to handle the loaded ropes. On a racing boat this deck layout is engineered for speed — see deck layout and sail controls. For every other term you will meet, the sailing terms glossary is the place to look.
Frequently asked questions
- What are the main parts of a sailboat?
- The main parts are the hull (the body of the boat), the keel (a weighted fin underneath for stability and to resist sideways slip), the rudder (for steering), the mast and rigging (which hold up the sails), the boom (the horizontal spar along the bottom of the mainsail), and the sails themselves (usually a mainsail and a headsail). The front is the bow, the back is the stern.
- What is the keel of a sailboat?
- The keel is a fin projecting down from the bottom of the hull, usually weighted with ballast. It does two jobs: its weight keeps the boat upright and stops it capsizing, and its fin shape resists the boat slipping sideways through the water, which is what lets a boat sail upwind. Dinghies use a lighter centreboard instead of a ballasted keel.
- What is the difference between the mast and the boom?
- The mast is the tall vertical spar that holds the sails up. The boom is the horizontal spar attached to the bottom of the mast that runs along the foot of the mainsail, holding it out and letting the crew control its angle. 'Boom' is also the thing to watch your head for — it swings across the boat when you tack or gybe.
- What do port and starboard mean?
- Port is the left-hand side of the boat and starboard is the right-hand side, as seen by someone facing forward towards the bow. They are used instead of left and right because they never change regardless of which way a crew member is facing, which avoids confusion. The front of the boat is the bow, the back is the stern.
- What is standing rigging and running rigging?
- Standing rigging is the fixed wire or rod that holds the mast up — the forestay, backstay and shrouds. Running rigging is the ropes that move: the halyards that raise the sails and the sheets that control their angle. In short, standing rigging holds things up, running rigging pulls things around.