Abstract Experimental studies were carried out on the non-linear hydroelastic vibrations of a cantilever circular cylindrical tank. Following the empty case (Part I of the study), experimental results for the case when the tank is partially filled with liquid are presented in this paper. Two polyester test cylinders with radius R = 240 mm, thickness h = 0.254 mm, and lengths L = 480 and 160 mm ( L R = 2.0 and 2 3 , respectively) were used. The tank was fully or partially filled with water having a free surface. The non-linearity of the response of the flexible wall was investigated by varying the liquid height. In the experiment, peculiar non-linear responses, e.g. subharmonic, superharmonic, combination responses, as well as a travelling response were observed. It was found that the degree of non-linearity depends on the vibration mode (i.e. on the circumferential wave number and the axial wave number of the shell), the length of the tank, and the height of the liquid contained therein. The influence of a floating thin film on the bulging responses was also examined.