 The Río de la Plata was difficult to navigate due to the extensive sand banks which reduced navigation to small draft vessels forcing the use of the few existing open channels, subject to frequent changes due to sediment accumulation and the changing winds.Martín García island, controls the west channel, which due to its relative depth was the obligatory path for any vessel with a draft of no more than 2 or 3 meters, who wanted to reach the interior rivers flowing into the Río de la Plata, such as the Paraná or the Uruguay rivers, closed to the west by an extensive sand bank.Facing the risk of losing control of the strategic island, and with the objective of gaining a base from which to attack the town of Colonia del Sacramento, occupied by the rebels, at the beginning of 1814 Romarate fortified the island and parked a flotilla of 9 vessels with 18 and 24 pounder artillery pieces.