The best person to whale watch with is Kim Beddall, founder of whale watching in Samana. Her company is Victoria Marine/Whale Samana. It is located on the side of Camilo Restaurant facing the central park. You can email her at kim.beddall@usa.net
The answer to the other part of your question, if memory serves, is that the wale watching season is from mid-January to mid-March when they are calving.
