wrote about seaweed that he feared would trap his ship and potentially hide shallow waters that could run them aground, as well as a lack of wind that he feared would trap them.

The sea may have been known to earlier mariners, as a poem by 4th-century author Avienius describes a portion of the Atlantic as being covered with seaweed and windless, citing a now-lost account by the 5th century BC Carthaginian Himilco