The plans prepared in 1627 by Don Luis Bravo de Acuña shows a number of defensive platforms, including the Seagate just to the South of the triangular shaped Baluarte de Santa Cruz [Bastion of the Holy Cross] which the British would later re-construct and re-name North Jumper’s Bastion. Juan Caballero’s 1779 map shows the platform as overlooking a small watering jetty [muelle de aguada] on its left hand-side. The Seagate would have been protected from possible attack by flanking fire from South Bastion in the North and La Torre del Tuerto further South. Closer support came from the Baluarte de Santa Cruz on its immediate right and the defensive towers along its left flank.
By the mid-16th Century much of the Line Wall along the Red Sands had fallen into disrepair and some sections had even collapsed. Such was the state of neglect that in 1540, a corsair raid led by the renegade slave Caramani infiltrated the town through the southern district of La Turba, sacking the city and taking many captives. After the raid, the southern defences were eventually repaired and protection to the actual city was further bolstered by the construction of Charles V Wall. In 1662, the engineers Genaro Mariá Aflito and Octaviano Meni proposed plans for new fortifications along the wall, including reinforcing the Torre del Tuerto to protect the New Mole which had been built in 1516.