Vermont Discovery Cruises is a division of Green Mountain Boat Lines. Green Mountain Boat Lines was founded in 1984 by Mike Shea with a 149-passenger paddle wheeler named the Spirit of Ethan Allen. For 11 years, the boat operated offering scenic, dinner and charter cruises on Lake Champlain. In 1995 a new 500-passenger the Spirit of Ethan Allen II began offering a wider variety of cruises and a larger capacity. In 2002, the new Spirit of Ethan Allen III began operations in Burlington, Vermont. The Spirit of Ethan Allen II was renamed the Spirit of Plattsburgh and moved to Plattsburgh, NY. In 2005, the Spirit of Plattsburgh was sold, and now operates as The Islander, serving Alcatraz Island.

Lake Champlain's past is rich with numerous ships offering overnight passage around the lake. Mike saw an opportunity to bring back the past. He purchased The Bonny Blue, an overnight cruise boat, from Blue Peter Lines in Virginia, and renamed her The Moonlight Lady in the summer of 2007. Over the winter months of 2007/ 2008 the Moonlight Lady underwent an extensive renovation with the addition of a top deck culinary theater and dining space, and new pilot house. The horizon and admiral decks were updated with new interior design and operational equipment. The redesigned Moonlight Lady begins overnight cruises in 2008.