Like many fish, whales surface only to pose for human photography and high-five low-flying seagulls. Snap interspecies salutations with today's Groupon: for $19, you get a 3- to 4-hour whale-watching cruise from Boothbay Whale Watch (a $38 value).

Boothbay's captain and highly trained crew steer passengers to the favorite haunts of whales, sharks, dolphins, and a variety of ocean birds. After launching from Boothbay Harbor, the expedition tours the inlet, inspecting landmarks such as historic lighthouses and a rock outcrop resembling a scowling Ralph Waldo Emerson. Upon reaching the whales' feeding ground, seafaring eyes can scour the water for roving finbacks, curious minkes, and ridiculous-looking humpbacks. Captain Wodan Vanderlaan, a 23-year Gulf of Maine veteran, maneuvers his ship to follow the first cetacean spotted, granting passengers firsthand appreciation of playful sea mammals, as resident expert Mechele Vanderlaan identifies each species and reels off facts about them.

Boothbay Whale Watch's 100-foot-long ship, the Harbor Princess, accommodates up to 149 passengers and contains marine-life-spotting equipment such as radars, GPS navigators, and a squad of elite scuba-diving nature-documentary narrators. Alcohol is banned from the ship, but the Harbor Princess's full-service galley ferries a range of light fare and beverages to echoing stomachs. Tour reservations must be made at least two to three days in advance.