Muelle General is the main boat dock for trips from Pátzcuaro onto the lake, especially to Janitzio. It is a practical place rather than a beauty spot: ticket windows, snack stands, boatmen calling departures, and families heading out for a few hours on the water.
Come in the morning for the easiest connections and calmer light on the lake. During Day of the Dead the pier becomes part transport hub, part crowd-control exercise, so leave more time than you think you need.