Rameswaram, Mar 13 (ANI): In view of frequent arrests made by Sri Lanka for crossing maritime boundary, Indian fishermen have demanded the immediate repair of a navigation tower at the Gulf of Mannar which would help them remain in their waters. A number of Indian fishermen have been held by Sri Lanka over the years for allegedly trespassing into its territorial waters. Navigational towers assist navigators in determining their position or safe course, or to warn them of dangers or obstructions to navigation.