From our local paper,
Fisherman Hendrik said he had been fishing in heavy rain near Lancang Island when he heard a "loud sound about fifty metres away from me and a big fall which caused big waves in the water".
"I was scared and had to focus on keeping my boat stable but after the water calmed, i saw many pieces of trash".
Some one living in the tropics saying it was heavy rain would indicate, to me at least, it was HEAVY.