Sailboat

Overview

A cruising sloop is a single-masted sailboat carrying one mainsail and one headsail, the most common rig for offshore and coastal cruising. Wind acting on the sails drives the boat forward, while a deep ballasted keel resists the heeling and sideways forces, letting the boat sail across and into the wind rather than merely downwind. This 38-foot monohull is built in glass-reinforced plastic with a fin keel and a spade rudder, and carries an electric saildrive for auxiliary propulsion in calms and harbors.

The boat is built around the Fiberglass Hull, a molded GRP shell, capped by the Deck Module. Stability and lift come from the bolted-on Fin Keel, whose lead ballast holds the boat upright and whose foil resists leeway. Steering is by the Rudder & Steering, a spade rudder turned through cables from a wheel. Driving force is developed by the Sail Set hung on the Mast & Standing Rigging, the keel-stepped mast and its wire standing rigging; the Running Rigging of halyards, sheets and winches hoists and trims those sails. When there is no wind the Electric Saildrive takes over, powered by the Electrical System lithium bank, and the Navigation Electronics suite handles GPS, depth and autopilot.

How it works

Sails work as vertical airfoils. As wind flows across the curved sail, it generates lift roughly perpendicular to the sail, which has a forward-driving component and a large sideways component. The keel converts that sideways force into forward motion by resisting leeway, and its ballast provides the righting moment that keeps the boat from being knocked flat. Trimming the sheets sets each sail's angle to the wind: eased for reaching, hauled in tight for beating upwind. By tacking, the boat zig-zags to windward, no point of sail being available dead into the wind. The standing rigging holds the mast up against these loads, the turnbuckles tension the shrouds and stays to keep the spar straight, and the wheel-and-cable steering turns the spade rudder to hold or change course. In calm or close quarters the through-hull electric saildrive spins a folding propeller for quiet auxiliary power.