Hi SallyK
Right then: First of all currency.
You can take Roubles with you - I understand that these can be pre-ordered in banks and other exchange facilities here in the UK. If you would prefer to wait until you are overseas, it can be difficult to exchange pounds into Roubles in Russia, as such, we would recommend you take cash in either Euros or US Dollars, ensuring that the notes are free from damage and marks. You should also be able to withdraw cash from an ATM in Russia. Please note, there is no currency exchange on board the ship but you can exchange currency in banks ashore. Passports are required to exchange cash.
For payments on board - you will receive a ship's credit card upon embarkation to which most on board expenses (optional tours, stamps, drinks, bar products) are debited; the total amount should be paid at the end of the tour by credit card (mastercard or visa) or cash. Laundry, tour photos and Matrioshka doll painting must be paid in cash. And. for all cash payments Russian Rubles are the only accepted currency.
Onto the electrical sockets - Rostropovich has 220 volt 2 pin European sockets in each cabin so a standard adaptor should be fine.
I hope all of this helps,
Kindest regards,
Julia