The harbor is turning into a giant bathtub for the city's summer festival, which begins on Saturday, and Thursday was a dress rehearsal.
Organizers say people will able to see the rubber duck from miles away. The duck, which is five stories high, is the work of Dutch artist Florentin Hofman.
Festival officials say the duck took three weeks to make and takes about a half-hour to inflate. The art has also made appearances in Japan, Brazil and throughout Hofman's native Netherlands.
The duck will remain in the harbor through the end of January.
ABC News contributed to this report.