The only organized tours of St. Petersburg -- and they are pretty good ones -- are with Duck Tours of Tampa Bay (tel. 727/432-3825), which runs 80-minute tours of downtown and the nearby waterways using reconditioned World War II amphibious "Ducks." These vehicles depart from the Pier daily from 11am to 5pm. The narrated excursions cost $19 for adults, $17 for seniors, and $9.95 for children 3 to 12, plus tax. Kids under 3 ride free. The same company has tours of Tampa as well. Note: As this book went to press, an insurance issue had temporarily suspended operations of Duck Tours. Call ahead to see if the company's back up and running before making any plans.