The Lembeh Strait is a narrow sea area 15 kilometers long and 2 kilometers wide. The water depth is 5 to 20 meters. The bottom of the sea is the volcanic rock topography. It is mostly sand formed by volcanic mud siltation. The water flow in the strait is stable all year round and the visibility is good. January-March is the rainy season, the best diving month is April-October, and the annual water temperature is maintained at 28°C/82.4°F, suitable for novice or fun divers.