We did the Baltic trip on NCL Dream 10th May
Take about $20-30 in local currency for all stops except Russia as Rubbles cannot be obtained. Anything else use a credit card.
Don't miss the trip down the Kiel Canal as this is the highlight of the cruise.
Get your vodka and caviar from Yelisev's in Nevsky Prospekt, the best vodka being marked as "Russian Standard".
In Copenhagen - don't use the ships trip to Tivoli Gardens ($25) but walk (i's about 20-30 mins along the waterfront) Entrance is 5 euros (about $5) if you want you could get a taxi back (about $10 but you will need Danish Krona)