Vegetius said that sailing was safe from May 27 to September 14 but that the two doubtful, or dangerous, periods ran from September 15 to November 11 and from March 11 to May 26.
Vegetius berkata bahwa dari 27 Mei sampai 14 September, laut itu aman. Tapi, dari 15 September sampai 11 November dan dari 11 Maret sampai 26 Mei, situasi laut itu tidak pasti.