The Baumhaus at the harbour entrance doubles as a bar in the warmer months, and the location — right at the mouth of the inner harbour, with views across the water toward the open Wismar Bight — is the best outdoor drinking spot in the city. In summer the terrace fills with a mix of locals, sailors, and visitors who have walked up from the old town. It is informal, sometimes noisy, and entirely consistent with the harbour setting.
Beer is the drink of choice, and the selection covers the main German lager styles alongside a few regional options. Come in the late afternoon, when the light on the water is good and the harbour is still active. On summer evenings the place gets busy; on a weekday afternoon in shoulder season you may have the terrace largely to yourself, which is arguably the better option.