There’s more than one way to reach this magnificent island...
Groix is easy to reach by boat, usually departing from the port of Lorient. But there is another option: a much smaller ferry departing from the port of Lomener (Ploemeur), which is also considerably smaller. The crossing to the island is shorter and includes commentary. Here are the contact details for both options:
Compagnie Oceane, from Lorient, year-round: http://www.compagnie-oceane.fr/
Laïta Croisières, from Lomener, in season: http://www.laita-croisieres.fr/
Compagnie Oceane, from Lorient, year-round: http://www.compagnie-oceane.fr/
Laïta Croisières, from Lomener, in season: http://www.laita-croisieres.fr/