In early 1520, Magellan’s fleet began searching for a passage through South America. At Punta del Este, optimism rose as no further land was visible to the south, prompting hopes of reaching the Pacific. Magellan ordered cautious exploration: two ships probed westward while others scouted southward. Regrettably, depth soundings revealed increasingly shallow, fresh waters, revealing they were not in a strait but the vast mouth of the La Plata River. The discovery dealt a severe blow to Magellan’s credibility, as his reputation largely rested on his promised knowledge of a western passage.