Device for winding and unwinding the lower part of fishing line (cast) is a part of equipment for fishing with hook, by which it is solved the problem of visibility in water of lower reinforced parts of lines made of materials visible in water. These parts represent one of the most loaded parts of fishing equipment, because they are subjected to large tensile and gliding stresses. The device includes a two-part housing in which there is the hollow cylinder on which the reinforced lower part of the line is wound by a blade coil spring. In the stage of attracting the fish, the reinforced lower part of the line remains invisible and in the stage of swallowing, tearing and pulling the bait with the device, reinforced lower part of the line is pulled out of the device. The pulled out, reinforced lower part of the line cannot be bitten through or torn off by the fish, that enables the reliable catch. The device is used as the bait and model or insert for natural and artificial fishing baits for fishing predatory freshwater and sea fish.