Transport to and around Ganvie is of course only by boat. The boats depart from the Lakeside village of Abomey-Calavi which is a short drive from Cotonou. You can purchase tickets at the office there.
My trip was pre-booked and our motor boat was covered to protect us from the sun. We also had a local guide who explained the fish farms we passed and and gave us a lot of information about Ganvie on the journey. It takes about 45 minutes to reach Ganvie and most trips take half a day. Ours was a full day as we visited other lake villages and had lunch.
Many people in the lake villages have their own canoe but if they don’t they can travel by water taxi which travels between the villages and Abomey Calavi regularly, carrying people and goods.
The only way to get to Ganvie is ofcourse by the sea. There are motorised boats and pirogues across the lagune from Abomey-Calavi, a 25 minutes ride by car from Cotonou. Getting from Abomey-Calavi and out to Ganvie takes about 1 1/2 hour to 2 1/2 hours depending on what type of boat you take.