Nautical charts are one of the fundamental elements to achieve safe navigation. Regardless of the type of boat or the instrumentation of the boat, our sailing trips make use of these nautical charts to ensure that our trip is as safe as possible.
In this article, we are going to learn more about the nautical chart. In this way, when you get on a sailboat with us and see this essential element for sailing, you will have a much clearer idea of its use and you will know what they are used for.
What are nautical charts and what are they for?
Nautical charts are graphical representations to scale of a maritime area where fundamental information for the navigator is displayed. Basically, a nautical chart is like a map, but it is specifically designed for an area of the sea.
In the same way as a map, a nautical chart is intended to guide navigators. It achieves this by providing very important information, for example, the depth of the water in a certain area or if there is any danger that needs to be taken into account when navigating. Information relating to the coastline may also appear, for example, the position of some ports or lighthouses.
These nautical charts also show relevant information to be aware of. Thanks to nautical charts, it is possible to know how fast the boat should move or if the area through which it is going to pass has some type of official protection. In addition, relevant information is also provided about the coast or the territory to which the waters belong.
Nautical charts are essential to be able to plan a sailing trip. Thanks to the information that appears on the charts, all kinds of risks can be avoided and, therefore, navigation is much safer.
How to Interpret a Nautical Chart
To interpret a nautical chart correctly, certain aspects must be taken into account. The first thing to know is the scale. Unlike maps, ocean scales are much larger, as the distances are greater. If you come across a nautical chart that has a scale of 1/10,000, it means that a meter on paper is actually 10,000 meters.
On a nautical chart you should also know what the Magnetic Declination Rose is. This chart with engraved circles appears on all nautical charts and is one of the most important elements, as it offers the difference between geographic and magnetic north.
If we want to represent the course of the sailboat on the nautical chart, it will be necessary to apply a correction. The Magnetic Declination Rose is directly involved in this complicated operation, as it is a fundamental part of the equation.
Nautical charts are full of numbers and symbols, so it is also essential to know them if you want to interpret a nautical chart without problems. To sum up, there are mainly two codes, one for the colour, phase and period of lighthouse lights and the other for the seabed.
An important aspect in this regard is that the abbreviations are presented in English, as it is the international language of the sea. You will find an “S” on the chart if the floor is sandy, “Sand”, an “ST” if it is stone, “Stone” or if it is mud, an “M” for “Mud” among many other examples.
Finally, on the sides of the nautical charts you can find indicators that refer to the system of parallels and meridians that the nautical chart has. Different hazards that must be taken into account may also be represented in it, for example, the presence of an iceberg.
Types of Nautical Charts
Nautical charts can be classified in different ways, so we can find different types. If we take into account the scale, we can find the general charts, which are those that encompass a large amount of coast and sea, to other smaller charts such as the charts of overheading or coastal navigation.
Then there are other types as well, for example, Fishing Charters that provide more information on the depth of the water with information on the fishing grounds or the type of seabed, Charts of Streams where the main currents are shown, the weather charts that affect the weather and then the electronic charts.
Electronic charts are the most modern and are types of nautical charts that are used in a chartplotter or GPS. Within this category we would also find different types such as vectors or RNCs, which are standard cards that have been scanned for use in these electronic tools.
Who Invented Nautical Charts
Many nations that entered the sea thousands of years ago have already documented the characteristics of the sea for safer navigation. It was the Spanish and Portuguese who began to make use of nautical charts as such in their explorations to the West Indies and the Americas.
Despite this, the Dutch would be the forerunners, since their nautical charts took into account aspects that the Portuguese or Spanish charts did not consider, for example, the indication of depths or dangers at sea.
As a curiosity, clay tablets were found in Mesopotamia around 2300 B.C . that showed the representation of navigable canals and rivers, which could be understood as an ancient approach to these nautical charts.
It would be in the nineteenth century, with the rise of navigation, that nautical charts began to be developed on a global scale. At first they would be private tasks, but with the passage of time public bodies would begin to make use of these nautical charts, especially because of the importance of military operations on the high seas.
