While crossing a river, one should offer oblations of water to his Pitris, naming them all. Indeed, when one comes upon a river one should please his Pitris with oblations of water.
जलं प्रतरमाणश्च कीर्तयेत पितामहान्। नदीमासाद्य कुर्वीत पितॄणां पिण्डतर्पणम्॥