Boal is an old and rare light-skinned white grape variety native to the volcanic island Madeira of Portugal. The grape is known under many manes, but the most common synonym is Malvasia Fina. Boal is an early-ripening vine, moderately susceptible to downy mildew and botrytis, and more susceptible to powdery mildew. It is a grape that produces alcohol-rich white wines with moderate acidity and a wide range of aromas. It is one of the four noble Port grape variety, producing sweeter styled Madeira than those of Sercial or Verdelho. The grape is as well-used for the production of the sparkling wines. The Boal Madeira is very rare due to the low quantity plantings and the decreasing use of fortified wines on a worldwide scale. Boal is also planted in the Canary Islands of Spain, where the grape is called Gual.