Will be in Zurich for two days prior to river cruise. We want to take a day trip into the alps. Any thoughts on this would be appreciated. We would like a small group tour that includes a train ride.
You would need a train to get from Zürich to the Alps.
My suggestion: Train to Luzern (70 minutes), boat to other end of lake, and train back to Zürich
If I may ask, why are you staying in Zürich? A better option would be to stay in the Alps, Luzern or the Berner Oberland.
Put “Zurich day trips” in your search engine. A large variety of options will appear.
I agree with Chris - stay in Luzern (you're basically right at the edge of the alps at that point and its much more beautiful than Zurich). As I recall, there are direct trains from the airport to Luzern (many more with changes at the Zurich main station (Zurich HB). Getting to Basel, where your cruise probably starts is also a snap from Luzern on the train.
In terms of day trips from Luzern, there are many - all of them gorgeous. Boat/steam ship rides on Lake Luzern, the Rigi, Pilatus, a day trip to Brienz, etc, etc.