The REPCET tool is a software system dedicated to navigation. Its aim, first and foremost, is to limit the risks of collision between large cetaceans and large vessels.

The concept is simple and is based on the following: every sighting of large cetaceans by watchkeeping personnel on board a vessel equipped with REPCET is transmitted by satellite in real-time to a server located on land. The server then centralises the data and sends out an alert to equipped vessels that are likely to be affected. The alerts are displayed cartographically on a dedicated screen on board.

The collaborative nature of the system means it relies on the density of commercial maritime traffic. Other vessels are also welcome to voluntarily contribute to the system by reporting cetacean sightings, especially military vessels, scientists at sea, whale watching operators, and pleasure boaters.

Input of a sighting

Input of a sighting

Consideration for the work of watchkeeping personnel on the bridge is one of the keys to the effectiveness of the system. That is why particular attention is given to the ergonomics of user interfaces, especially in facilitating reporting of whale sightings.

The input interface thus allows rapid entry of sightings into the system, automatically linking them to various essential data (name and position of the vessel, distance and bearing of the animal, its species, number of individuals, etc.). A relative positioning tool has been specially designed for this purpose.

Presentation of the alerts

The mapping interface is designed to display the alerts sent by the server. It allows the user to visualise the alerts on a topographic map and to easily zoom in and pan around the map. An intuitive display allows rapid location of dangers and their nature, in order to adapt the watch on the bridge for example. Detailed information on the alerts can also be called up (origin, time, species and number of individuals).

Repcet mapping interface

In addition to accurately positioning the whale sightings, the system calculates and displays the associated risk zones. These shaded, evolving circular areas correspond to the risk of encountering the initially detected animal. The display is intuitive, allowing the level of risk within the mapped zone to be easily and quickly understood.

Customisable alarms allow crew members to anticipate potential encounters, thus avoiding the necessity of continuous monitoring of the mapping screen.

After a certain time period, the zone is deemed no longer at risk and the circles disappear. The position of the initial sighting however remains for 24 hours, identifiable by a different symbol. In this way, potentially dangerous sectors where there have been abundant recent whale sightings are easily identifiable.

Integration of prediction models for cetacean distribution

Cetaceans do not move about randomly in their habitats. Their presence is linked to the abundance of their food source, which in turn depends on physico-chemical and biological factors over distance and time. Based on this observation, statistical models have been developed that predict zones of cetacean presence according to environmental data provided by satellite such as temperature, currents, salinity, and chlorophyll levels.

Collaboration with CNRS is currently underway, to integrate an early cetacean distribution model into the REPCET system. The interface is thus capable of displaying high risk zones of whale presence. This experimental approach will be modified and improved as new versions of the system are developed.

Alert and display of dangerous floating objects (AVURNAV)

CROSSMED has agreed to collaborate with REPCET, which is also used as an additional means of broadcasting AVURNAV (emergency alerts for navigators).

Interactive Terminal

The REPCET system can be accompanied by an interactive terminal for the use of passengers on equipped vessels. This pedagogical tool provides encyclopaedia-style information on Mediterranean cetaceans, as well as displaying the position of recent whale sightings on a topographic map. It encourages the involvement of equipped companies, at the same time providing information to passengers with a public-awareness message on the protection of cetaceans.

Contribution to research

The system sends the cetacean positions transmitted by equipped vessels to a database on land where they are recorded and linked to meteorological data provided by Météo France. The database is thus built up over time, and is made available to the scientific community with a twofold objective: to improve our knowledge of cetaceans, AND eventually to improve the performance and precision of the REPCET system.

Use of REPCET thus contributes in two ways to the ecological responsibility policies of maritime companies: protecting large cetacean populations against the risk of collision, as well as contributing to research on these animals.

Smartphone application


Currently being developed, a smartphone application "REPCET mobile" will give the possibility to other contributors such as sea professionals to send observations to the system in order to improve its efficiency. Users will only be allowed to send cetacean observations but not to receive any, in order to reduce risks of using it for commercial whale-watching purposes.
All information on the REPCET application are available here (French).

If you are an informed leisure boater and are interested in downloading the application and join the network, you can send an email explaining your motivations to the following address: appli [at]

Predicted evolution of the system

Integration of sensors and automation of detections

REPCET is designed to evolve with technology. Relying initially on visual detection in its earliest version, it is designed to integrate all types of sensors (on-board infrared sensors, underwater passive acoustic detection systems, etc.)

Thus in future versions, the system will be capable of automatically processing the positions of large cetaceans detected by these sensors, and as a result optimise its performance particularly at night.

"Marine Area" interface

A web-based interface is envisaged for the use of Marine Protected Area (MPA) managers who may benefit from development of the system. The interface will allow users not only to monitor sightings of large cetaceans in real-time, but also to browse the history of sightings and develop charts showing the distribution of the animals over time. The aim is thus two-fold:

a. to provide a logistical tool for research within the marine area (use of real-time data)
b. to provide a tool for monitoring the whales seen by equipped vessels (use of mapping history).



If you work on board a car ferry, cargo ship or a cruise ship, on the bridge, try out the REPCET system using this simulator. Record your whale sightings to inform the other vessels in the network, consult the map of last known sightings, increase the watch in high risk zones, consult the "whale forecast" using the presence prediction models… in short, REPCET as if you were there!