Helsinki → Tallinn, Estonia → Haapsalu, Estonia
The ferry departs 1:30pm, so boarding is probably 12:30. That leaves a comfortable 11am checkout and a little Helsinki morning cafe and walk around before hitting the terminal.
The ride to Tallinn is 2 hours, so arrival is 3:30pm.
The ride to Haapsalu is short, so there's a little time for Tallinn and Haapsalu explorations.
Leaving at 1:30pm leaves the morning for breakfast and walking around Helsinki before bording. Then 1h40m and 107km to Haapsalu leaves time to explore Tallinn and Haapsalu.
depart duration prices arrival 07:30 2 h 38.90 € 24 € 09:30 10:30 2 h 38.90 € 43 € 12:30 13:30 2 h 38.90 € 43 € 15:30 ** PURCHASED, RESERVATION NUMBER 75318614 16:30 2 h 40.90 € 56 € 18:30 18:35 4 h 40.30 € 35 € 22:45 18:35 80.30 € 65 € 08:00 overnight option 19:30 2 h 38.90 € 43 € 21:30 22:30 2 h 38.90 € 24 € 00:30I like the 10:30am or 1:30pm options as they allow breakfast in Helsinki and some time in Tallinn followed by 1.5hr ride to Haapsalu.