It's a hoot -- or should I say a quack? Whether or not you opt to use the duck call whistle included in the tour price to blow at the folks you pass in the street, you'll get a kick out of this combination land-and-sea tour. You'll be transported in a six-wheel-drive amphibious vehicle (originally created for British troops during the Cold War) through Austin's historic downtown and the scenic west side before splashing into Lake Austin. Comedy writers helped devise the script for this 1 1/2-hour tour, so it's funny as well as informative.