Spinnaker

Amante Choate 48 photo D Ramey Logan

Bear of Britain spinnaker

420 Class Dinghies with spinnakers

Asymmetricspinnaker

Corsica Classic 2013 Aigue Blu

Spinnaker is a type of sail primarily used on sailing yachts and racing boats to provide additional propulsion downwind. Unlike traditional sails that are designed to catch wind from the side, spinnakers are large, lightweight, and often colorful sails that balloon out in front of the boat when deployed. They are designed to catch the wind from behind, making them particularly effective for sailing with the wind, a condition known as running or downwind sailing.

Design and Types

Spinnakers are made from lightweight, synthetic fabric, which allows them to billow out, creating a large surface area to catch the wind. There are several types of spinnakers, each designed for specific sailing conditions and boat types. The most common types include the symmetrical spinnaker, the asymmetrical spinnaker, and the gennaker.

Symmetrical Spinnaker

The symmetrical spinnaker is designed to be symmetric along its vertical axis, which means it can be used on either side of the boat. It is traditionally used with a spinnaker pole, which is attached to the mast and the lower corner of the sail, to help control the shape and direction of the sail. Symmetrical spinnakers are often used in traditional racing and cruising yachts.

Asymmetrical Spinnaker

The asymmetrical spinnaker, also known as an "asym" or "cruising spinnaker," does not require a spinnaker pole for deployment. It is attached at three points: the top of the mast, the bow, and the clew (the lower corner of the sail). Asymmetrical spinnakers are easier to handle than symmetrical ones, making them popular among cruising sailors and for short-handed sailing.

Gennaker

A gennaker is a hybrid sail that combines elements of a genoa (a type of jib) and a spinnaker. It is used for reaching, which is sailing at an angle to the wind, and is faster than both the genoa and the spinnaker when sailing at certain angles. Gennakers are also asymmetrical and do not require a spinnaker pole.

Usage

Spinnakers are primarily used in racing due to their ability to significantly increase a boat's speed downwind. However, they require careful handling and coordination among the crew to deploy, trim (adjust), and douse (take down), especially in strong winds or rough seas. The process of managing a spinnaker can be complex, involving precise timing and maneuvering.

Racing and Cruising

In sailing races, the use of spinnakers is a critical strategy for gaining speed and advantage downwind. Skilled crews can deploy and douse spinnakers quickly during races to maximize their boat's performance. In cruising, spinnakers are used to enhance the sailing experience, allowing boats to travel faster and more comfortably downwind.

Safety and Handling

Handling a spinnaker requires knowledge and experience, as improper use can lead to accidents or damage to the sail and boat. Safety measures include monitoring wind conditions, ensuring the crew is trained in spinnaker maneuvers, and having the appropriate safety equipment on board.