Le Palais, the main harbour in Belle-Ile, has an enclosed wet dock. If the lock is closed or the harbour is full, you can always find somewhere to anchor upstream of the lock.
It is a lively place with a lot of shops and a daily market. For up-to-date practical information, please see the town’s official website.
If you like reading, then you must go to the Liber & Co bookshop-café perched on the ramparts.