Terry is the Destination Specialist on the Mariner, however from the 19th July, Roger Condon (Former Travel Concierge Manager) will be taking over the role until the end of the Alaska Season.
As for the different styles between Terry and Sandra..... Sandra is more of a historian and lecturer, whereas Terry is more of a storyteller and works from her own experiences.
Both are excellent orators and always add to any cruise or destination.