Spinnaker

A spinnaker (or spi ) is a veil of before very light and very hollow hoisted with the bearing paces. Its name would come from the comments caused at the time of its invention. Skeptics as for his stability, the spectators would have declared “ It is going to make her spin ” ( that will make capsize the boat ), from where name spinmaker , then spinnaker .

Symmetrical Spi

The symmetrical form is most traditional. The not of listening of the veil is maintained by a Tangon placed at the wind, about perpendicular to the apparent wind and in the prolongation of the Bôme.

The purpose of the boom is to draw aside the spi remainder of the Gréement, and its operation requires much more ropes than for a normal veil: not only listening and Rope, but also a arm for the orientation of the boom, one hauls-high and one hauls-low boom for the horizontality of this one… The Empannage under spi traditional request to make pass the boom of an edge on the other, the arm and listening invert their roles then.

The symmetrical spi is especially effective with large-loose and the back wind.

Asymmetrical Spi

Of more recent development, but in the line of veils of before very hollow (jibs balloons, precursors of the symmetrical spi, and become ensuites gennakers), the asymmetrical spi was conceived first of all for the race: the speed of the boats increasing, the apparent Vent approaches the axis of the boat, one thus needed veils more efficcaces for the paces close to the wind (and in particular for the multihull , and unquestionable fast monoshells: ULDB, planing center-boards of Australian inspiration…).

The boom became a Bout-dehors, fixed at the stem of the boat. Easier to use, more stable, it is used from small releases until large loose. It cannot be used to go up the wind, and is of a poor output to the back wind. It is gradually adopted also by the sailing ships of pleasure, especially because of absence of maneuvres of boom: it maneuvre like a sail of before traditional.

To operate under spi

Unstable and fragile, to operate under spi is delicate. The transfer is excluded, it is necessary of Empanner to change Amure.

The main difficulty consists in preventing the sail from deflating, which could be to him fatal in high wind conditions. Owing to the fact that it only is little maintained during the passage of the boom, it can also strongly become deformed, causing imbalances of the boat which can go until violent auloffées to the outcome often very wet.