NOVELTY - The device has water guiding passages (6) created by fastening together two flexible elastomer foil layers. Bundles (7) are formed from the neighboring passages, where ends of the passages of neighboring bundles are connected to each other with a connection passage (8) arranged in parallel such that an end of the passages of the given bundle is connected to the ends of the passages of the neighboring bundle on a side of the given bundle and another end of the passages of the given bundle is connected to the ends of the passages of the neighboring bundle on another side of the given bundle.    USE - Device for heating water using solar energy for a human use application. Uses include but are not limited to bathing application, household water application, hot water application and swimming pool application.    ADVANTAGE - The device utilizes heat-absorbing pipes running in parallel to be divided into groups including a small number of pipes, where the heat-absorbing pipes within the groups are connected in parallel when the groups are connected to each other in series, thus allowing heat-transfer to be fast, the water flowing in the device to remain in the device for a long time to allow rise in temperature to be significant and the temperature of entire mass of water to reach a level suitable for bathing. The device utilizes shape of the connection passages to be formed other than in a straight line, thus reducing stresses caused by deformation and risk of the device becoming damaged and increasing lifetime of the device. The device has a sleeve to be formed at an edge of the device and safely positioned vertically, thus reducing amount of space required and risk of the device being stepped on.    DETAILED DESCRIPTION - The flexible elastomer foil layers are black colored foil layers.    DESCRIPTION OF DRAWING(S) - The drawing shows a top view of a connection opening of a solar water-heating device.    Water guiding passages (6)    Bundles (7)    Connection passage (8)    Connection openings (11)    Fastening lines (19)