A line source and a line receiver are used to measure values of group and phase velocity for circumferential waves around a thin‐walled air‐filled aluminum cylinder when the cylinder is immersed in water. These are believed to be the first experimental measurements of phase velocity of circumferential waves around a thin‐walled cylinder. Also, experimental values of attenuation are measured for pulses. These experiments are carried out for frequencies from 50 to 200 kHz, corresponding to a value ofkafrom 15 to 60. A theoretical analysis based on the equivalent mechanical impedance of a thin‐walled elastic shell is developed and numerical values are computed for comparison with the experimental data. The phase velocity measurements agree with computed values in their dependence on frequency, but the values are systematically too large by 2%. However, the experimental values measured for pulses do not show good agreement with theory.