Question: Do you know if it’s possible to circumnavigate Scandinavia via Holland, the Baltic Sea, St. Petersburg, the Belomorsk Canal, the White Sea, the Norwegian Coast, returning to Holland?
Answer: It has been done. I think the UK Cruising Association did a cruise in company that way some years ago. The tricky bit is the Russian canal. From what I understand it is important to have a Russian with you who can manage things and it is better if several boats travel in company. I understand that that part of Russia can still be pretty wild, with graft (bribes) and stealing. The rest of the cruise should be fairly straight forward.
Update: John Vallentine successfully undertook a voyage through Russia in 2014.