Proas do not tack, they shunt – meaning they go in both directions sailing forward and… well, forward. It is a fairly simple process of letting go the main sheet, turning the rudders, sheeting in and away you go…

Shunting like this is not as quick as tacking, and a lot slower than gybing. However, it is generally easier and much safer than both, and the worse the conditions, the more obvious the difference is.