Shom C Nautical Chart – Atlantic Ocean

Introduction

The Shom C nautical chart of the Atlantic Ocean is a flat paper nautical chart, generally supplied rolled, intended for route planning and navigation in the various areas of the Atlantic Ocean covered by the hydrographic charting of the French Hydrographic and Oceanographic Service (Shom). Depending on its scale, it can be used for an ocean crossing, offshore navigation, passage planning, or navigation closer to the coast and port approaches.

The Atlantic is an exceptionally vast maritime area. It includes the French, British, Spanish and Portuguese coasts, the Bay of Biscay, the British Isles, the Azores, Madeira, the Canary Islands, the Moroccan and West African coasts, as well as transatlantic routes connecting Europe with the Caribbean and the Americas. A Shom C Atlantic Ocean nautical chart must therefore be selected primarily according to the geographical area, intended route and required scale.

Shom charts are hydrographic documents designed to represent accurately the information required for navigation: depths, soundings, depth contours, hazards, shoals, reefs, wrecks, channels, aids to navigation, lights, landmarks, ports, anchorages and other nautical information.

Shom C Atlantic chart: what is it used for?

The main characteristic of a Shom C chart is its flat presentation. Unlike a folded Shom L chart, it is designed to be rolled and stored in a tube. Its large format provides a substantial cartographic surface, making it easier to follow a maritime route on a chart table.

Shom C charts of the Atlantic are available at very different scales. Some cover extensive oceanic areas for passage planning, while others are much more detailed and cover a specific coastline, bay, port or anchorage.

For example, the Atlantic catalogue includes offshore charts such as Shom 6815C, covering the eastern part of the North Atlantic Ocean at a scale of 1:10,000,000, as well as much more detailed charts such as Shom 6286C, covering the Tabou anchorage at a scale of 1:10,000. This illustrates the importance of scale when selecting a nautical chart.

A small-scale chart provides a very broad geographical overview, whereas a large-scale chart represents a smaller area with considerably more detail.

Main areas of the Atlantic Ocean

The Shom C Atlantic Ocean nautical chart category covers numerous navigation areas.

North Atlantic and Europe

Charts may cover the major maritime routes between Europe and the North Atlantic, including:

• the English Channel and its approaches;

• the Bay of Biscay;

• the French Atlantic coast;

• the British and Irish coasts;

• the Celtic Sea;

• the approaches to Spain and Portugal;

• routes towards the Azores;

• the North Atlantic.

For navigation departing from France, ports such as Brest, Lorient, La Rochelle, Bordeaux, Bayonne and Saint-Jean-de-Luz may be departure or passage points depending on the planned route.

Portugal, Spain and the Iberian Peninsula

The European Atlantic also includes the approaches to ports such as Vigo, La Coruña, Porto, Lisbon, Setúbal and Cádiz. These areas are important for both coastal navigation and offshore passages towards the Atlantic islands.

Azores, Madeira and Canary Islands

The Atlantic archipelagos are important stages for offshore navigation between Europe, Africa and the Caribbean.

Shom C charts can be used to plan routes around the Azores and their approaches. Ports such as Ponta Delgada, Horta and Angra do Heroísmo are examples of Atlantic destinations commonly associated with ocean passages.

Further south, Madeira and the Canary Islands are also major waypoints for transatlantic route planning. The ports of Funchal, Las Palmas, Santa Cruz de Tenerife and Arrecife are located on routes connecting Europe with the Caribbean.

Eastern Atlantic and West Africa

Shom C Atlantic charts also cover areas off the West African coast, including sectors around Morocco, Western Sahara and West Africa.

Ports such as Casablanca, Agadir, Safi, Dakar, Nouakchott, Abidjan, Monrovia, Lomé, Cotonou and Lagos are examples of ports and harbour areas associated with this maritime region.

The catalogue includes, for example, Shom 6113C, covering the area from Cape Blanc to Cape Verde, as well as detailed coastal charts around certain African ports and anchorages.

Atlantic crossing towards the Caribbean and the Americas

The Atlantic Ocean is also essential for long-distance passages between Europe and the Caribbean or the Americas.

A transatlantic passage may connect the Canary Islands or Cape Verde with destinations such as Fort-de-France, Pointe-à-Pitre, Bridgetown, Saint Martin or the Bahamas.

In this context, offshore charts are used to study the complete route and plan the different stages. They are generally complemented by larger-scale charts for island approaches, channels, ports and anchorages.

What information is shown on a Shom C chart?

Depending on its scale and geographical coverage, a Shom C nautical chart may provide information including:

• soundings and depths;

• depth contours and bathymetric information;

• shoals and navigation hazards;

• reefs and rocks;

• wrecks;

• channels and passages;

• buoys and other aids to navigation;

• lights and their characteristics;

• landmarks and coastal reference points;

• ports and harbour facilities;

• anchorages;

• regulatory limits or information represented on the chart;

• inset plans providing greater detail for specific areas.

Reading a nautical chart always requires consideration of its scale. A general Atlantic chart cannot replace a detailed coastal chart when approaching a port or anchorage.

Planning an Atlantic crossing with Shom charts

For a passage between Europe and the Caribbean, charting should be considered as a coherent set rather than as a single chart.

Chart preparation may include:

• a general chart providing an overview of the ocean route;

• one or more offshore charts suited to the passage;

• more detailed charts of archipelagos and coastal areas;

• harbour approach charts;

• anchorage and channel charts where required;

• nautical publications and sailing directions for the areas concerned;

• an atlas or navigation manual to complement the cartographic information.

This approach is also relevant for passages to the Azores, Madeira, the Canary Islands, Cape Verde or the West African coast.

Differences between Shom C, L, G, Z and Raster charts

Shom C and Shom L charts contain the standard information of a nautical chart, but their presentation differs mainly in how they are handled and stored. Shom C charts are flat and generally rolled, whereas Shom L charts are folded.

Shom G charts add sedimentological information describing the nature of the seabed. They may be of particular interest to professional fishing activities, seabed studies and certain marine operations.

Shom Z charts correspond to Zonex charts. They reproduce standard nautical chart information and add an overprint showing relevant exercise and firing areas.

Raster charts are digital reproductions of nautical charts, including GeoTIFF-format products. They can be used in compatible software environments.

The importance of chart scale

Scale is one of the main criteria when selecting a Shom C Atlantic Ocean nautical chart.

For an ocean crossing, a small-scale chart provides an overall view of the route. For coastal navigation, a larger scale provides more detail. For a harbour approach or anchorage, a very large-scale chart may be required.

It is therefore common for a navigator to use several charts for the same voyage: a general chart for the overall picture, an offshore chart for the ocean passage, followed by coastal or harbour charts for the final stages.

Shom C Atlantic charts and nautical publications

A nautical chart is only one element of the documentation required for properly prepared navigation. Depending on the area, it can be complemented by nautical publications, sailing directions, atlases, navigation guides, regulatory documents and navigation manuals.

For an Atlantic crossing, it is particularly important to distinguish between planning the ocean route and approaching land. The information required offshore is not necessarily the same as that required when entering a port, following a channel or selecting an anchorage.

Combining charting appropriate to each stage with suitable nautical documentation provides a coherent view of the entire route.

Why choose a Shom C chart for the Atlantic?

A Shom C chart is particularly suitable when a navigator wants to work with a large-format flat paper chart. Depending on its scale, it can be used for passage planning, offshore navigation or certain coastal navigation situations.

When selecting the appropriate Shom C Atlantic chart, it is important to check:

• the exact geographical area;

• the departure and destination ports;

• planned stopovers;

• the scale;

• the type of navigation intended;

• any required coastal approaches;

• the relevant ports and anchorages;

• the edition and available corrections;

• compatibility with the other charts used for navigation.

Conclusion

The Shom C Atlantic Ocean nautical chart category includes flat paper charts covering a vast range of maritime areas, from the European coasts to the North Atlantic, West Africa, the Azores, Madeira, the Canary Islands and the major transatlantic routes towards the Caribbean and the Americas.

The choice of a Shom C chart primarily depends on the geographical area and scale. A general or offshore chart is suitable for preparing an ocean passage, while a larger-scale chart is required for coastal navigation, harbour approaches or anchorages.

Shom C charts can be complemented by Shom L, G, Z or Raster formats according to specific requirements, as well as nautical charts from other publishers, publications, atlases and navigation manuals. For the Atlantic, this complementary approach is particularly important given the size of the ocean and the wide variety of possible navigation scenarios.

FAQ – Shom C Atlantic Ocean nautical chart

What is a Shom C Atlantic Ocean nautical chart?

It is a Shom paper nautical chart, presented flat and generally rolled, covering an area of the Atlantic Ocean. Depending on its scale, it may be intended for offshore navigation, ocean passage planning or coastal navigation.

What is the difference between a Shom C and a Shom L chart?

Both contain the standard information of a nautical chart. Shom C charts are flat and generally rolled, whereas Shom L charts are folded to A4 format, making them easier to store and handle onboard.

Which Shom C chart should be used for an Atlantic crossing?

One or more charts should be selected according to the planned route, geographical coverage and scale. An offshore chart can be used to prepare the ocean passage, while more detailed charts are required for island, coastal and harbour approaches.

Do Shom C charts cover the Azores?

Yes. The Shom catalogue includes charts covering the Azores, particularly for navigation planning around this Atlantic archipelago.

Do Shom C charts cover the Canary Islands and Madeira?

The Atlantic catalogue includes cartographic documents covering different areas of the Atlantic and its archipelagos. For navigation to Madeira or the Canary Islands, the exact geographical coverage and scale of the required chart should be checked.

Which Shom chart should be used for navigation between France and the Caribbean?

A France-to-Caribbean passage generally requires a combination of charts suited to the different stages of navigation: Atlantic route planning, offshore passage, approaches to the Caribbean islands and local navigation around the islands.

Why is chart scale important?

Scale determines the level of detail shown. A small-scale chart covers a large area with less detail, while a large-scale chart covers a smaller area with more information useful for coastal and harbour navigation.

What is a Shom G chart?

A Shom G chart is a sedimentological chart. It contains standard nautical chart information together with additional information about seabed characteristics and sediment distribution.

What is a Shom Z chart?

A Shom Z, or Zonex chart, includes an overprint showing the boundaries and identification of exercise and firing areas used by maritime forces. The corresponding information should be interpreted together with nautical documentation and Notices to Mariners.

What is a Shom Raster chart?

A Shom Raster nautical chart is a digital version of marine charting, notably distributed in GeoTIFF format. It is intended for use with compatible charting or navigation software.

Is one Shom C chart enough to cross the Atlantic?

This depends on the route, geographical area and scale. An ocean crossing generally requires several levels of charting to provide appropriate coverage offshore, along the coast, around archipelagos and for harbour approaches.

Which Atlantic ports may be covered by these charts?

Depending on the charted areas, examples include Brest, La Rochelle, Bordeaux, Lisbon, Vigo, Cádiz, Casablanca, Dakar, Las Palmas, Santa Cruz de Tenerife, Funchal, Ponta Delgada, Horta, Fort-de-France and Pointe-à-Pitre. These examples illustrate the diversity of navigation areas associated with the Atlantic.

Why complement a Shom C chart with nautical publications?

The chart represents the geographical and hydrographic environment required for navigation. Sailing directions, guides, atlases and navigation manuals can provide additional information about ports, approaches, currents, local conditions, anchorages and specific navigation characteristics.