18th edition of Saint John's celebrations on the Vltava River. NAVALIS is a commemoration of the best-known Czech saint and Prague native, Saint John of Nepomuk, patron of all people of the water. The festivities include a solemn mass in the Cathedral of St Vitus, St Wenceslas and St Adalbert, a procession from the Cathedral across Charles Bridge to Křižovnické Square, and a Baroque concert on the Vltava River.