Vilassar de Mar is a village near Barcelona, in the county called Maresme, in the Mataró maritime Province. It had one of the most outstanding Catalan maritime communities along eighteenth and nineteenth centuries, both in shipping activities and shipbuilding. One of the most important seafaring dynasties was the Sust. It started with an Italian castaway arrived in the eighteen century. Since then, shipbuilders, mates and ship masters carried the surname Sust. Using primary sources from the family archives, the author explains the history of its member and at the same time the history of this maritime community. We can find in it the careers of the Sust shipmasters that lived the transition from sail to steam. It must be said that interesting original materials from this family are now preserved at the Arxiu Municipal de Vilassar de Mar and the collections of the Museu Marítim de Barcelona.