摘要:The paper presents the study of the strength parameters of wood samples from the retaining structure, working for about 60 years in an aggressive sea water environment. Samples from the variable water level zone and situated in the watered ground were tested. Non-destructive examinations were performed using the following methods: the stress wave technique and the ultrasonic wave technique. The results presented below can lead to the conclusion that both methods: the stress wave by Fakopp Microsecond Timer device and the ultrasonic wave by Sylvatest Trio correspond with each other and result in similar outcomes. However, in order to obtain more detailed and comprehensive information on the elements properties, more research should be conducted.