Experiments have been performed to determine the length for convergence or closure of a vertical, hollow annular water jet due to the action of surface tension forces. The data agree well with theoretical predictions up to the maximum velocity where reliable data could be obtained (4.4 m/s). These experiments extend the range of confirmation of the theories in terms of the dimensionless parameter, Nc ≡ We/Fr2, from about 0.01 to over 100. The stability of the annular jet subjected to natural and external disturbances is also discussed briefly. Finally the results of a series of experiments on the flow spreading or splitting due to the presence of wedge-shaped obstacles in the path of the annular jet flow are presented.