Indonesia's Meteorology, Climatology and Geophysical Agency (BMKG) has warned of waves of up to 4 meters in parts of Indonesian waters through Sep 24, with the southern and central Makassar Strait, a key shipping route for coal from Kalimantan, among areas facing waves of 1.25-2.5 m. The warning could slow barge and transshipment operations, although there is no clear evidence so far of widespread disruption to coal shipments. Meanwhile, prolonged dry weather remains a more immediate logistics concern, with low water levels on the Barito and Mahakam rivers already affecting coal transportation in parts of Kalimantan.