A crew member (3rd R) gives explanations during a public visit on the French Tara Oceans boat on May 18, 2013, in Lorient, western France, on the eve of its departure for a 25.000km tour of the Arctic ocean that will last seven months. French Tara Oceans boat navigates across all the world's major oceans to sample and investigate microorganisms in the largest ecosystem on the planet.