Grijalva River
Perry had received reports in April that the Mexican commander in Tabasco, Col. Domingo Echagaray, had strengthened the city's defenses and built obstructions in the Tabasco River (present day Grijalva River). Perry assembled the Mosquito Fleet, consisting of the steamboats "Scourge", "Scorpion", "Spitfire", and "Vixen", plus the brigs "Washington", "Stromboli", and "Vesuvius", and the merchant schooner "Spitfire", off Frontera on 14 June and began moving upstream, towing 40 ship's boats carrying 1,050 men and seven surfboats with a field piece each.