From May through September what is the best transportation from St. Petersburg to Stockholm? We prefer traveling by train or boat. An over night boat is preferable over a plane but would consider a flight if it were reasonable compared to the boat. Thanks
This will provide a broad overview of the choices
St Peter line has direct overnight boats from St Petersburg to Stockholm. Only once or twice per week though so might not fit your schedule. Book at https://stpeterline.com/
Another option is train to Helsingfors or Turku and then overnight cruise ferry to Stockholm. Book train at www.vr.fi and the ferry at www.vikingline.com or www.tallinksilja.se
Or you can fly direct with SAS. Book at www.flysas.com