Sailboat study of dolphins in the French archipelagos

  • Cetaceans
  • From the Channel Islands to Southern Brittany
  • Adults, teenagers aged 12 and over
  • Six stays in summer 2024
  • From €2,356.90 / €801 after tax deduction*.

This summer 2024, our partner is organizing ship-based trips between Granville and Ile D'yeux. On the program: monitoring cetacean populations, studying jellyfish and collecting plankton and microplastic with Manta nets. All cetacean missions here.

Study and protection of bottlenose dolphins

The aim of the scientific project is to study bottlenose dolphin populations in mainland France: Molène archipelago, Sein archipelago, Chausey island, Jersey island and Guernsey island. The presence of bottlenose dolphins is a good indicator of ocean health. Analyzing its movements and characteristics provides scientists with information on the marine ecosystem. In recent years, however, dolphin groups have dispersed. 

Jellyfish, plankton and microplastic

The scientific sailing trips will enable us to monitor dolphins, as well as jellyfish. Plankton and microplastic surveys are also part of the program. Studying and protecting cetaceans requires precise demographic monitoring and analysis of their social interactions.

Are there leaders? A group hierarchy? Are there any solitary individuals? Are groups constant in number? These are all important questions to answer. The data collected during the stays will contribute to the national monitoring of this megafauna. The measurement of microplastics is carried out in partnership with OceanEye, whose laboratory analyzes the samples collected. 

Your participatory science action

For the 2024 season, six sailing trips are planned between Granville and Ile D'yeux (see dates and prices).
You'll be watching the cetaceans from the sailboat. When you spot a group of dolphins, the boat will approach from a safe distance, allowing you to observe their behavior without disturbing them. Cetacean watching is done with the naked eye, binoculars and a compass. 

The photo identification technique

The method used to study cetaceans is photo-identification. This means taking photos of their dorsal fin to identify them individually. For bottlenose dolphins, the fin is unique, a bit like our fingerprints. You'll have identification cards at your disposal. The fin photos will then be filed in a database. This database enables researchers to find out when and where each individual has been seen.

Participation in navigation

You'll regularly put a plankton net in the water and, once you've fished, you'll examine a few drops of water with a binocular magnifying glass. In addition to specific observation time, you'll learn how to operate the sailboat, with an introduction to maneuvers and marine cartography. You'll take part in the various tasks of life on board: cooking, resting, plankton, weathero....

During this participatory science trip you will learn about

  • Photo identification
  • Non-intrusive wildlife observation techniques
  • Sailboat operation, navigation and life on board.
Price: From €2,356.90 / €801 after tax deduction*.

Stay 1: July 14 to July 21, 2024 (ages 12-17)

You'll be sailing throughthe Anglo-Norman archipelago. Embark at Granville and disembark at Saint Quay Portrieux. You'll explore the Guernsey and Jersey archipelagos, and the Minquiers plateau, all rocky islets that provide refuge for a rich biodiversity, much appreciated by the bottlenose dolphin. You'll also see a colony of Northern Gannets, a seabird decimated in August 2022 by avian flu.

Stay 2: July 21 to July 28, 2024 (ages 12-17)

You'll sail along thenorth coast of Brittany and the Mer d'Iroise. Embark at Saint Quay-Portrieux and disembark at Brest. This route is dotted with islands where you'll encounter pods of dolphins. Before arriving in Brest, the Ouessant archipelago will be explored in search of larger cetaceans such as rorqual whales.

Stay 3: July 28 to August 4, 2024 (ages 12-17)

You'll sail throughthe southern Mer d'Iroise to the archipelagos and islands of southern Brittany. Embarkation in Brest, disembarkation in Lorient. This area is a transition to the warmer waters and gentler landscapes of southern Brittany. You'll explore the Glénans archipelago, then the island of Groix. Several species of dolphin frequent these islands, including the smallest cetacean, the porpoise.

Stay 4: August 4 to August 8, 2024 (Adults) 

You'll be sailing in southern Brittany, Lorient, towards the Ile d'Yeu, and experimenting. Weather permitting, you'll sail at night. Embarkation and disembarkation in Lorient.

Stay 5: August 11 to August 18, 2024 (ages 15-25)

Departing from Lorient, you'll explore the island of Groix and the Glénans archipelago. Embarkation in Lorient, disembarkation in Roscoff.

Stay 6: August 18 to August 25, 2024 (ages 12-17)

Embark at Roscoff, disembark at Granville. Departing from Roscoff, you'll explore the many islets of Brittany's northern coast, including Les Sept Iles and Ile de Bréhat, before arriving at Granville, the end of your cruise. Several species of dolphin frequent these waters, including the Bottlenose dolphin and Risso's dolphin. 

Tax deductible *

  • 6 stays (see dates and rates) 
  • For teenagers and adults depending on departure dates: 12 - 17 years / adults / 15 - 25 years
  • A passport is required for certain trips (sailing in the Channel Islands).
  • Participants must be able to swim. An aquatic fluency certificate must be provided upon registration.


You'll be staying aboard a 12.6-meter sailboat. It includes 4 cabins, a large central area with kitchenette and toilet.


Stays are supervised by a professional skipper and a scientific educator. 

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The NGO partner

Partner NGO Objectif Sciences international has Special Consultative Status with the UN (ECOSOC) and is a member of the AAAS Science and Human Rights Coalition. Specializing in scientific trips, science and participatory research, the NGO believes that education is the driving force behind the Sustainable Development Goals. It offers a range of participatory science trips for adults and minors. All OSI programs here

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