Impulse turbine with self-pitching-linked guide vanes has been developed especially for wave energy conversion in Japan. Based on the study, a large turbine has been fabricated and is operating on the west coast of India. Large turbines need substantial supports about which the guide vanes pivot. Such supports affect the turbine's performance. In this article, results of experimental investigation on the effect of guide vane support geometry on starting and running characteristics of the turbine are presented. The geometrical variations studied include two different cross-sectional shapes and different support lengths.