India's southernmost territory (Indira Point) on Great Nicobar Island of the Nicobar Islands is approximately 84 miles or 135 km to the north from the Indonesia's northernmost territory on Rondo Island. Centered 21 km or 13 mile northwest of Rondo, between Indonesia and India, there is a submerged sandy and rocky coral shoal with a least depth of 51 m. Island is surrounded by a mile (1.7 km) wide reef which has steep marine slope on its edges. On the southern edge of island's reef there are small rocky islets, 14 in total lying at a distance between 0.9 to 1.7 km. Between these islets and Weh Island there is 16-20 km or 3-3.5 leagues wide safe navigable channel. Before the advent of modern shipping, the shipping between Rondo and Weh Islands was considered safer due to calmer seas.