Concierge.com's insider take:

Put your skepticism aside: This tour of Boston on WWII amphibious vehicles is actually fun and informative (with the occasional historical embellishment). The brightly colored Ducks motor around the city then plunge into the Charles River to catch skyline views of downtown—once you're in the water, you might even get to pilot. The personable guides (sorry, "conDUCKtors") have all passed rigorous tests about city history and lore. You might learn about the chemical reaction that causes some Beacon Hill houses to have windowpanes of bluish-purple glass (and why this is desirable), and the sticky situation the city found itself in after the Great Molasses Flood of 1919. Tickets sell out fast, so if you're intent on "ducking," reserve ahead online (up to five days in advance). Tours depart from (and tickets are sold outside of) the Museum of Science and New England Aquarium; there's also a ticket booth in the Prudential Center.—updated by Jon Marcus

Available daily from March to November and Saturdays and Sundays in December 9 am until one hour before sunset.