The Río de la Plata is the widest river in the world and one of the most dangerous for navigation

It is usually considered that the Rio de la Plata or Mar Dulce as it was called at the time of its discovery is the widest river in the world. And to a great extent it is, because there is nowhere else such an extension of fresh water as wide as that found in this river, which can also be defined as an estuary due to its mix of sea and river waters. At the western end, near Colonia del Sacramento, its width is just over 40 kilometers, but at the southeastern end, in the area adjacent to an imaginary line between Punta del Este in Uruguay and the Argentine coast at Cabo San Antonio, the maximum width is 225 kilometers. With an area of ​​30,400 km2, it is also one of the largest river mouths on the ocean coasts of the planet.

What we now call the Río de la Plata does not lead to any region rich in this metal and to a large extent it is the result of a historical contradiction of navigators who were looking for the great silver deposits of Upper Peru through this route and the name finally stuck.

The native peoples called this hydrographic macro-accident with words that we do not know, although we know that the Guaraní peoples called it “pará guazú” (from “pará” extensive waters, sea and “guazú” large). In other words, a large area of ​​marine waters. Even today the main arm of the Paraná River in its delta is called “Paraná Guazú”.

It is difficult to imagine the geological history of the body of water that we now call the Río de la Plata.

Geologically, the Río de la Plata is of recent origin, that is, a little over 10,000 years, which in geology is a very short time. Let's say that about 15,000 years ago the current bottom of the river was dry land, it was emerged and constituted a low plain in the axis of which a fluvial channel was established, a kind of paleoplate that emptied into the Atlantic Ocean forming a silt-sandy delta at the height of the imaginary line Punta del Este-San Antonio.

At that time, large amounts of silty dust (loess) arrived, which crossed and accumulated on the surface of that ancient plain (today covered by water) and towards the adjoining undulating areas and which would constitute the majority of the agricultural soils in the coastal territories on both shores.

The climate of that period was semi-arid and colder but there was enough vegetation to support several large mammals such as glyptodonts (giant species of finches), mylodons and megatheria (giant sloths) and mastodons (relatives of elephants). We must point out that at that time (about 10,000 years ago) the first human communities arrived in this region. We know that they were responsible for the extinction of the giant species we were talking about. These human communities have probably also been able to witness the flooding processes of the low plains that gave rise to the formation of the Río de la Plata as we know it today.

Today it is a roughly triangular water surface that extends for 325 kilometers in a northwest to southeast direction. Its surface is 30,400 km2.

The southwestern shore, which corresponds to Argentine territory, is made up of low plains, often flooded, while the northeast shore is higher, made up of beaches and rocky points, with a foreland of gently undulating relief, corresponding to Uruguayan territory.

The Río de la Plata is shallow. The average depth does not exceed 10 meters reaching its maximum depth is 25 m. on the imaginary line that determines its outer limit. There are numerous areas with much shallower depths that are called "banks" including the extensive Banco Ortiz, with a sandy-loam composition off the Uruguayan coast of San José with depths of 2 to 4 meters, and the less extensive Banco Inglés but with less depth ( 0.5 to 3 meters) composed of rocky substrate locally covered with sand. Other smaller banks are Banco Archimedes and Rouen. These banks are important because they represent obstacles to navigation and are responsible for numerous shipwrecks.

On the other hand, the wide opening of the Río de la Plata gave and gives rise to the entry of salty ocean waters during periods of lower fluvial flow and high tides and the advance of fresh waters contributed by the Paraná and Uruguay rivers during periods of heavy rains and low tides. Salt water tends to advance below fresh water with relatively little mixing. This characteristic regime of the Río de la Plata is called the estuarine regime.

The Río de la Plata is a powerful aquatic entrance to the continent that was used for maritime access to the main rivers. On the southwestern shore, the port of Buenos Aires was established in 1580) and on the northeast, the port of Montevideo. At different times other ports were established (Colonia, Maldonado, La Plata) but they never had the importance of these two main ports mentioned above.

The Río de la Plata is generally navigable (depth of the channels of more than 8 meters) but due to the presence of shallow banks it requires accurate bathymetry to avoid shipwrecks. A regime of frequent storms and fog has made navigation even more difficult.

We can say that in fact, in a certain way, the history of the Río de la Plata is the history of the great shipwrecks that occurred in it.

The first obstacle that appears to ships sailing into the Río de la Plata from the oceanic northeast is the island of Flores. It is located about 10 kilometers from the nearest coast and 25 kilometers from the port of Montevideo.

It is 1,800 meters long and a maximum of 300 meters wide. It has been occupied since colonial times. A field hospital, a powder keg and finally a pesthouse were installed there, for the quarantine of slaves. In the Portuguese era, a lighthouse was built and there was a headquarters for the Military Command and the Post and Telegraph Office, a Maritime Sanitary Station for ships with sick people that had a Disinfection Department.

About 18 kilometers south of the island of Flores and 28 kilometers from the nearest Uruguayan coast is the so-called

English Bank. It is an old rocky elevation, perhaps granite, which, when the old plain was flooded, remained as an elevation of the bottom of the river and whose highest peak is about 0.5 m from the surface of the water, with breakers on its northern edge appearing during the extraordinary downspouts..

It extends from north to south with a length of 18 kilometers and almost 4 kilometers wide with a perimeter of 75 kilometers and an area of ​​17,000 ha. Its average sounding of 5 meters. for the entry and exit of overseas ships from the ports of the Río de la Plata and the rivers that flow into it. From this area starts the access channel to the port of Montevideo and the Punta Indio channel that from the Recalada Pontoon (a ship maintained by Argentina for boarding pilots) leads to the port of Buenos Aires and to the others in the Plata basin.

The space between the island of Flores and the English bank constitutes the gateway to the Río de la Plata and the ports both in the estuary and in the interior rivers.

Most of the shipwrecks are related to the coastal restingas and rocky points, as well as those that occurred in the English Bank and on the Island of Flores itself.

In particular, the shipwrecks caused by the English bank have been numerous and the salvage of the vessels or their crews very difficult due to the distance to the coast and the lack of references.