The kala pani (lit. black water) represents the proscription of the over reaching seas in Hinduism. According to this prohibition, crossing the seas to foreign lands causes the loss of one's social respectability, as well as the putrefaction of one's cultural character and posterity.

Can Brahmin travel abroad?

This especially applied to Brahmins, as there was fear that travel abroad prevented a Brahmin from performing various rites and rituals in the prescribed manner at the prescribed time. ... There are Vedic verses that suggest (but not conclusively) awareness of the sea and sea-travel nearly 3000 years ago.

Why are Brahmins the highest caste?

Many believe that the groups originated from Brahma, the Hindu God of creation. At the top of the hierarchy were the Brahmins who were mainly teachers and intellectuals and are believed to have come from Brahma's head.