Centerboards

Part of speech: noun

Definitions

1. Movable fins mounted on the bottom of sailboats to provide lateral resistance and improve directional control while underway
2. Retractable keel-like blades located amidships under small sailing vessels that prevent sideways drift and enhance stability
3. Adjustable underwater panels on sailboats that can be lowered to counteract side forces and aid in steering and balance during navigation

Etymology: Centerboards are a plural form of "centerboard," so the history belongs to the singular. The word is a plain compound: "center" joined to "board," with the sense that the board sits along the boat's centreline, between the hulls or in the middle of the keel. Its parts are English, and the compound describes the object's position rather than its function. The idea behind the board is what makes the name fit. Unlike a fixed keel, a centerboard slides or pivots down through a slot in the hull, so the sail can grip the water without the boat drawing too much depth when the board is raised. Sailors could then shallow the draft for beaching or shoal water and still have lateral resistance when needed.

Synonyms: daggerboards, keels