"Quiberon, they reinvent artisanal fishing". In Quiberon, Simon Le Gurun, in his early forties, is a new generation fisherman. Three years ago, he decided to change the way he works by responding to an emerging demand: to sell his fish alive!

"Toulon, behind the scenes of the naval base". The place is huge and yet it is almost invisible. A veritable "city within a city", the Toulon naval base employs 23,000 people, both civilian and military, on a daily basis in the heart of an area of 1500 hectares. "Love at first sight in Porquerolles". It's called love at first sight. When Edith and Marc Frilet, originally from Marseille, discovered the island of Porquerolles 46 years ago, they fell in love with it

7000 kilometers from metropolitan France, far from the cold and dark seabed of the West Coast, the Atlantic Ocean reveals a completely different face; A marine paradise with warm, crystal clear waters, and ecosystems of rare richness.

"Living with the Storm". In Brittany every winter, from Ushant to Saint-Malo, storms punctuate the lives of the inhabitants of the coast and the islands. In the corsair city, every time there is a high tide coupled with a storm, there is a great upheaval. The city huddles as it waits for the spectacle of the giant waves; "In Guilvinec, a tide in heavy weather". Le Guilvinec in southern Finistère is a port that lives and breathes with fishing. On board the "Bara Pemdez", a 24-metre trawler, Yannick Affagar and his four sailors keep watch relentlessly, day and night; "The Amoco-Cadiz Disaster"

"Red coral, the treasure of the Cerbère-Banyuls reserve". The Cerbère-Banyuls reserve has just been granted the status of "World Refuge for the Sea". It is also the oldest marine reserve in France. For forty-five years, guards have watched over it. Among them, the Italian biologist Lorenzo Bramonti; "Gruissan, a model of fairness". Benjamin Bes, a young fisherman, is passionate about his job. In Gruissan, he perpetuates the deep respect of local fishermen for their lagoon. In this centuries-old prud'hommie, decisions are taken by show of hands and fishing areas are drawn by lot to avoid favouritism

A summer at the sea with Thalasa proposes to discover this Friday evening on France 3 Brittany alongside enthusiasts such as Erik Orsenna, diver Yves Gladu or navigator Eugène Ruiguidel. The opportunity to spend some tasty moments with real characters on the most beautiful sites of the French coast. Eugène Riguidel, great navigator, old "anar", and defender of almost lost causes, invited to a poetic walk between the islets of the Gulf of Morbihan and the tiny islands of Hoëdic and Houat. Off the port of Concarneau, the Glénan have almost no human presence during the winter. Nathalie Deliou, ranger of the nature reserve, introduces you to a unique plant: the Glénan narcissus, which only grows in this part of the world.

Founded by divers Ghislain Bardout and Emmanuelle Perié-Bardout, the "Under the Pole" expeditions have invented a capsule that allows you to stay under the sea for several days at a depth of 20 meters: every diver's dream! Passing through Polynesia, the explorers welcome scientists and specialists in coral reefs, which are increasingly threatened by global warming. Maybe the opportunity to film a rare event: the spawning of the coral! After twenty years in mainland France, Ismaël Patu Huukena, a Marquesan native wants to rehabilitate the Polynesian wisdom and environmental values dear to his ancestors. He set himself a sporting and spiritual challenge: to swim to five of the fourteen islands of the Marquesas archipelago! An opportunity to fully commune with the Pacific Ocean and the marine animals that inhabit it.

Brittany, the thriving seaweed business. It is a little-known treasure, hidden at the bottom of the Iroise Sea: it is the largest field of algae in Europe. This Breton green gold, coveted for its richness and exceptional diversity, has been exploited for the food industry for several decades by seaweed vessels in a highly regulated framework. Off the coast of Aber-Wrac'h, in Finistère, the "Rara-Avis", a three-masted schooner, welcomes young people from all walks of life on board. At the age of 24, Peter and Martin, in search of meaning, dropped everything on the ground to embark on this exceptional human adventure.

Girolata, living at the end of the world Accessible only on foot or by boat, the village of Girolata sees its population increase tenfold in summer. Right next door, listed as a UNESCO World Heritage Site, the Scandola Marine Reserve is a victim of its own success. Officials say they are worried. Every year, Pierre-Ange Guidicelli organizes a trimaran expedition around Corsica. A 1,000 km sailing trip to raise awareness among tourists about the invasion of plastics. Franck Bruno lives in a hut near Bonifacio, without water or electricity. Having had his leg amputated, he agreed to share this exceptional Corsican nature with other disabled people to boost their morale and the desire to move forward.

Between the bay of Mont-Saint-Michel, the Cap de La Hague and the Vire estuary, the Cotentin is a land of extremes, which comes in a multitude of settings: steep cliffs, immense beaches or inaccessible rocks.

Head for the Atlantic coast between Royan and Les Sables-d'Olonne. Nature shaped by the ocean, the wind, the tides. A nature that forges temperaments too. We will meet young people who have made the engaging, demanding choice to live by and for the sea: an artist, a fishing skipper and a sailor.

Thalassa offers sailing on the Mediterranean coast, from the Frioul Islands to La Ciotat. On this stretch of coastline, unspoilt natural areas sometimes rub shoulders with historic industrial sites.

Thalassa propose d'aller naviguer sur la côte méditerranéenne, des îles du Frioul à La Ciotat. Sur ce bout de littoral, des espaces naturels préservés côtoient parfois des sites industriels historiques.

Thalassa criss-crosses the English Channel off the coast of Normandy, from Cherbourg to the Chausey Islands. A maritime territory turned upside down by Brexit and the upcoming appearance of a border in the middle of the sea. How are we preparing to experience the event on both sides of the Channel? In Cherbourg, shipowner Sophie Leroy is worried about her fishing grounds, which have historically been on the English side. Reports: Immersion with the fishermen of Cherbourg during Brexit - Antoine Mora Starting a new life on the Ile de Chausey

Arnaud Gérald, the gifted freediver: Arnaud is 24 years old. He discovered freediving on the coast of the Phocaean city at the age of 16, a revelation and a desire that never leaves him. Let's meet this freediving prodigy whom the sea saved from school failure by teaching him to breathe... Listening to the sea: In Cassis, a young Italian scientist puts down her microphones to "listen to the sea". In Toulon, Hervé Glotin, a computer science professor and bio-acoustician, seeks to learn about the life of large marine mammals, without approaching them, without disturbing them or even seeing them, simply by listening to them.

On the small island of Hoëdic, off the coast of Quiberon, it was necessary to save the school, which was threatened with extinction. Yannick Moisson, a teacher in love with the sea, is committed to taking up the challenge.

Sur la petite île d'Hoëdic, au large de Quiberon, il fallait sauver l'école menacée de disparition. Yannick Moisson, un instituteur amoureux de la mer, s'est engagé à relever le défi.

In this programme, Thalassa travels along the Atlantic coast, from the island of Noirmoutier in the Vendée, to the island of Oléron in Charente-Maritime. How can we travel and consume differently? In a less polluting way and in an eco-responsible approach? Thanks to the De Gallant, an old rig that takes its time, a collective of islanders from Noirmoutier is betting on developing local agricultural production, and favouring a zero-carbon means of transport. How can we recycle polyester pleasure boats that often end their lives abandoned in ports or at the bottom of gardens without polluting?

In Brest, the Maistrance school is an institution of the French Navy, accessible from the baccalaureate, which trains future non-commissioned officers. In Tréguier, we met Jean-François Delvoye, who developed the expedition sailboat of his dreams.

Cléa, Benjamin and Cosme, both 22 years old, chose to interrupt their studies for a few months to measure the impact of the lockdown on plastic pollution. In Marseille, Guillaume Valès, a climbing guide, has a passion for the Calanques.

We sail along the Breton coast, from the Côtes-d'Armor to the Iroise Sea, to discover preserved and unique natural areas; Our first port of call will allow us to discover the unexpected consequences of the lockdown on the coast.