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.
A quicker way to shunt has been developed by the racers. Instead of bearing away, the boat is luffed head to wind. When the vmg drops, the sails are sheeted on to the new tack. This stops the boat and the rudders are rotated. As the sheets are pulled on, both rudders steer the boat back to the new tack. On a schooner, the aft rig is sheeted on first. If crew are available, they move forward on the windward hull to speed the turn. Similarly aggressive use of rudders, sheets and crew will also speed up a gybe/shunt.