The author presents Slavic beliefs and mythic notion of water as the dividing line between the world of the living and the world of the dead. Such a notion is rarely explicitly present in Slavic oral material. However, it is possible to trace it in particular customs and beliefs. One of the most interesting such customs is the custom of enclosing some money into the coffin for the fare to the island of the dead across the river. In some places people believe that a soul goes into another world across a bridge, foot-bridge, or a hair. Although narratives don't explicitly tell that bridge or hair lead across the water, we can conclude so on the basis of evidence about customs in the death occasion, when people in the same area put foot-bridges across the water to provide a soul faster entrance to the other world. Even in Christianised belief of the other world, which should be divided in heaven and hell, located one with the other, we can find out that hell actually replaced water in pagan beliefs.