Cumulonimbus: cloud forming a towering mass with a flat base at fairly low altitude and often a flat top, as in thunderstorms. oxforddictionaries
The Cumulonimbus cloud laying rain over the ocean. The sun is obscured by thick and dark clouds at low altitudes that seem flat on the bottom.
I shot photographs of cumulonimbus cloud today in the Indian Ocean from the position of Mount Gurutee, Aceh Jaya, Sumatra.
Traditional fishermen never get stuck with dangers when sailing, thanks to their experience of understanding through the symptoms that will occur.
The traditional Acehnese fishermen are very familiar with cumulonimbus clouds, they learned through experience of all natural phenomena at sea. But they use different terms about natural phenomena, the term is understood only by themselves. Traditional fishermen in Aceh are dominated by lowly educated people, but they are in the knowledge of astronomy inherited from generation to generation. They are not aware of the science they have.
@curiesea, I need your comment as a traditional Aceh fisherman.
