It was what accidental deaths did to people, made everybody's sea floor irregular and uneven, causing tidal currents to collide, surge upward, thereby resulting in small yet volatile eddies churning at everybody's surface. (In the more dangerous cases, it created a lasting whirlpool in which the strongest swimmers could drown.)

Special Topics in Calamity Physics (ed. Penguin UK, 2013) - ISBN: 9780241968963