Before you book a ticket with Tallink from Stockholm to Riga, a little warning. Travelled recently with Tallink and would NOT recommend them. Both trips were spoilt by the constant adverts over the loudspeakers in the cabin. You cannot turn these off and even if you ask reception to stop them, they will not. So you are bombarded (and that is the word) with adverts for perfume, childrens toys, supermarket items, lottery tickets etc. And it starts again in the morning. Not only that, but the music onboard is now very poor, which is I assume, due to all the cutbacks.
Slow boarding and disembarkation also spoilt the trip. Forgot to mention about the high prices onboard, they are now much higher and are far from cheap. They are also slower than before, and the conbination of a very slow crossing, constant advertisements in the cabin over the loudspeakers and poor onboard entertainment, would make us choose a flight next time.