You may want to check the "roll Calls " over at Cruise critic and see if someone is looking to share tours
Most people book the tour a year in advance.
Enjoy the cruise
Alexandr Pushkin, Carnival-Holiday, HAL-(old)Westerdam, Orient lines-Marco Polo, Royal Olympic-Olympic, NCL-Dream, Dawn-Princess, ACCL-Grande Caribe, Oceania-Insignia (3), Regatta(4) Marina (1) St Lawrence Cruise Lines-Canadian Empress
Scenic River cruise June 11,2012