Ochi is a powerful spying spell in which the songcaster plants a gândac, or bug, near the person or thing being observed. Shells, with their ability to capture sound, worked best.
In Deep Blue, Baba Vrăja cast an ochi to call the six mermaids to the Iele. The five mermaids they tried casting ochis. Serafina was only able to see around a corner. Ling had been able to see into Baba Vrăja's study. Neela and Becca had seen the Malacostraca. Ava was able to hold her vision of Abbadon for thirty seconds.