When your guide book tells you that you will visit the “Venice of Portugal”, it is pretty hard for that town to live up to your expectations. So, to get to the point immediately, this wasn’t Venice.
Aveiro is a sea town and sits on the Ria de Aveiro, with a large shallow lagoon close to town. Both salt and kelp are taken from the lagoon and sold in what seems like every shop in town. There are boats in town called moliceiros, which are kelp boat, that ride in the town’s canals. The older part of town has sidewalks and squares with traditional Portuguese hand-laid pavement in fancy patterns.