The purpose of the research is to solve the problem of delivering sunken timber to processors while maintaining the quality of wood in shallow depths. When rafting logs in bulk, a huge number sank. Their raising was carried out mainly at sites where deposits were concentrated, as a rule, on large rivers. The bulk of the timber rafting routes were along numerous small rivers. Clearing these rivers of sunken timber is largely hampered by the problem of delivering it to processors while maintaining wood quality in conditions of low flow depth. Solving this problem is the goal of this work. The methodological basis for solving problems to achieve the set goal was the provisions of hydrostatics and the branch of knowledge related to water transport of timber. As a result of the work performed, a device design has been proposed that ensures transportation of timber raised from the bottom during the cleaning of small rivers under the surface of the water, which prevents the rapid deterioration of their quality.The collapsible structure consists of parallel pontoons connected at the ends by transverse beams and at the bottom by intermediate flexible connections. Analytically, mathematical dependencies were obtained that connect the parameters of the proposed device and the characteristics of logs raised from the bottom. Based on these dependencies, a methodology and recommendations for substantiating these parameters have been developed. The information provided makes it possible to manufacture the proposed device with a preliminary justification of its parameters corresponding to local conditions, thereby helping to clear small rivers of sunken timber and preserve their quality during transportation.