Sail - Sail Types

Sail Types

Modern sails can be classified into three main categories:

• Mainsail,
• Headsail,
• and Spinnaker or downwind sail (also termed Kite). Special-purpose sails are often a variation of the three main categories.

High-performance yachts, in particular some catamarans such as the International C-Class Catamaran, have used or use rigid wing sails, which are said to provide better performance than traditional soft sails. In particular, a rigid wing sail was used by Stars and Stripes, the defender who won the 1988 America's Cup, and by USA-17, the challenger who won the 2010 America's Cup.

Most modern yachts, including bermuda rig, ketch and yawl boats, have a sail "inventory" which usually includes more than one of these types of sails. Although the mainsail is “permanently” hoisted while sailing, headsails and spinnakers can be changed depending on the particular weather conditions to allow better handling and speed.

Mainsails, as the name implies, are the main element of the sailplan. A "motor" as well as a rudder for the boat, mainsails can be as simple as a traditional triangle-shaped, cross-cut sail (see Sail Construction below). In most cases, the mainsail isn’t changed while sailing, although there are mechanisms to reduce its surface if the wind is very strong (a technique called reefing). In extreme weather, a mainsail can be folded and a trysail hoisted to allow steerage without endangering the boat.

Headsails are the main driving sails when going upwind (sailing towards the wind). There are many types of headsails with Genoa and Jib being the most commonly used. Both these types have different subtypes depending on their intended use. Headsails are usually classified according to their weight (that is, the relative weight of the sailcloth used) and size or total area of the sail. A common classification is numbering from 1 to 3 (larger to smaller) with a description of the use for example: #1 Heavy or #1 Medium/Light. Special types of headsails include the Gennaker (also named Code 0 by some sailmakers), the drifter (a type of Genoa that is used like an asymmetrical spinnaker), the screecher (essentially a large Genoa), the windseeker and storm jib. Certain Genoas and Jibs also have battens which assist in maintaining an optimal shape for the sail.

Spinnakers are used for reaching and running (downwind sailing). They are very light and have a balloon-like shape. As with headsails, there are many types of spinnakers depending on the shape, area and cloth weight. Symmetrical spinnakers are most efficient on runs and dead runs (sailing with wind coming directly from behind) while asymmetric spinnakers are very efficient in reaching (the wind coming from the rear but at an angle to the boat or from the side).