Russian visa requirements are complex but should not be feared. Numerous visa services exist to help in this area. See the Get In section of the article on Russia for information. The visa is not required for 72 hours if you arrive to St.Petersburg by ferry.
By plane
Pulkovo Airport IATA: LED | ICAO: ULLI (http://www.pulkovoairport...) serves a wide variety of destinations both international and domestic. Terminal 1 serves domestic flights, selected international charter flights and low-cost airlines, while Terminal 2 is reserved for international connections. The airport is located approximately 17 kilometers south from the center.
By bus
The cheapest, although by no means the most comfortable way of reaching Saint Petersburg from neighboring countries are long distance buses. Buses from Belarus, Ukraine, Germany, Finland, the Baltic states and Scandinavia stop at the main bus station Avtovokzal.
Metro: Ligovskii Prospekt far away from metro.
By ship
Finnlines (http://www.finnlines.com/...) has a two and a half day journey cruise from Lübeck two times weekly via Sassnitz and Ventspils.
Summer cruises and ferry services from Helsinki, Finland and Tallinn, Estonia appear and disappear at irregular intervals, often at short notice. St. Peter line (http://www.stpeterline.co...) has started visa free cruises from Helsinki, Tallinn and Stockholm to St. Petersburg.
Passenger boats also operate on the inland waterway "Volga-Baltic" which links Moscow, the River Volga and Lakes Onega, Ladoga and Neva.
To get out, you could try your luck for Freighter travel, although the port is very large. It would be easier if you have connections in the port. Try to find a dispatcher (http://www.ansc.ru).
Nearly all the major cruise lines Princess, Norwegian, Royal Caribbean, Holland America, Carnival, Celebrity, MSC, etc. offer a Scandinavia/St. Petersburg itinerary, and many stay overnight to allow shore excursions to Moscow. Azamara has itineraries that dock for three days/two nights. If you join a cruise tour of St. Petersburg then you don't need a Russian visa, but you have to stay with the tour.