Boats & Parts

Pick a hull, then take it apart. Drag to rotate, pinch or Ctrl + scroll to zoom, and click any part - the mast, the keel, a winch - to see what it is and what it does. Two boats here: a cruising keelboat and a catamaran. The sails are left off the models and detailed on their own further down the sheet.

Class drawingKeelboat
Building model…
Drag to rotate · pinch or Ctrl + scroll to zoom · click a part

The sails

On the model above the sails are left off so the spars and rigging read clearly. Here they are shown separately, each on its own diagram, so every edge, corner and control line of the mainsail and the genoa reads clearly on its own. These drawings are a fixed reference, not to scale.

01 Mainsail Set behind the mast
MAINSAIL Head Luff Bolt rope Leach Foot Tack Clew Gooseneck Secondary reefing Secondary reefing point Primary reefing Primary reefing point Main halyard Topping lift Boom vang Cunningham Mainsheet
02 Genoa Set forward, on the forestay
GENOA Head Luff Leach Foot Tack Clew Genoa sheet Genoa halyard
Mainsail edge Genoa edge Running rigging / controls Reef lines Reefing cringles Standing rigging (context)
Head
The top corner of the sail, hoisted to the masthead by the halyard.
Tack
The lower forward corner - fixed at the gooseneck on the main, at the stem on the genoa.
Clew
The lower aft corner, where the foot meets the leach and the sheet attaches.
Luff
The leading edge - up the mast for the main, along the forestay for the genoa.
Leach
The trailing (aft) edge of the sail, running from head down to clew.
Foot
The bottom edge of the sail; on the main it runs along the boom.
Bolt rope
The rope sewn into the luff and foot that slides into the groove in the mast and boom to hold the sail.
Main halyard
The line that hoists the mainsail and tensions its luff. (The genoa has its own halyard.)
Topping lift
A line from the masthead to the boom end that holds the boom up when the sail is lowered or eased.
Boom vang
A tackle (“kicker”) from the boom down to the mast base that stops the boom lifting, controlling leach tension.
Cunningham
A control line near the tack that tensions the lower luff to flatten the sail in a breeze.
Mainsheet
The main control line, from the boom to the deck, that trims the mainsail in and out. (The genoa sheet trims the genoa.)
Gooseneck
The hinged fitting that connects the boom to the mast.
Primary / secondary reefing
The first and second reef lines: reduce sail area in stronger wind by pulling a lower row of the sail down to the boom.
Reefing points
The reinforced cringles (and small reef ties) at each reef line that become the new tack and clew once reefed.
Genoa
A large headsail that overlaps the mast - bigger than a jib, it powers the boat upwind and on a reach.