Bolívar

The Department of Bolívar fronts Colombia's central Caribbean coast around the historic walled city of Cartagena de Indias, with the long Bahía de Cartagena bay sheltering the working port behind the colonial walls and the open Caribbean coast at La Boquilla running east to the Magdalena delta at Barranquilla. The tide here is a small mixed semidiurnal signal characteristic of Caribbean coasts at this latitude. Mean range at the Cartagena harbour gauge is about 0.4 metres, with spring tides reaching close to 0.6 metres and neaps dropping close to flat. The astronomical signal is small because the Caribbean is an enclosed-but-deep basin and the propagating Atlantic tide enters mostly through the Yucatán Channel and the Greater Antilles passages, with significant phase damping by the time it reaches the South American coast. What matters more on a day-to-day basis is meteorological tide. The trade winds blow steadily from the north-east across the open Caribbean and lift apparent water level on the windward (eastern) side of the Bahía de Cartagena by 20 to 40 centimetres during sustained events; the same wind builds the swell at La Boquilla. The defining hazard is hurricane-season storm surge, though Cartagena sits at the southern edge of the Caribbean hurricane belt and rarely takes a direct strike — most landfalling Caribbean hurricanes track north of about 15° latitude into the Greater Antilles or the Yucatán. The defining cultural feature is the colonial-era walled city. The 11-kilometre stone walls and the San Felipe de Barajas fortress above the city were built by the Spanish from the 1580s through the 1700s to defend the gold and silver shipments from Peru that staged through Cartagena to Spain via Havana. The walls front directly onto the harbour at the Baluarte de Santa Catalina and the Baluarte de San Lucas. The working port behind the walled city, the Bocagrande beach corridor, the ferry to the Rosario Islands offshore, and the snorkellers reading the inner-shelf coral at low water all read the table for different windows. The Centro de Investigaciones Oceanográficas e Hidrográficas (CIOH) of the Colombian Navy publishes the authoritative tide tables.