The wacky quacker is the noisemaker you get on a Ride the Ducks tour. But hit the road with rival operator Bay Quackers and you hear a similar sound. They give tours of the city and both of these amphibious tour companies take riders for a bay trip south of AT&T Park.
They operate modifications of the trucks developed during World War II.
This business over the bird call flap has become a new battleground. Ride the Ducks is suing Bay Quackers.
Ride the Ducks, out of Atlanta, says its sound has been trademarked for more than 10 years. Vice president Bob Salmon says "it's one of the things that makes our duck tours different."
But locally-owned Bay Quackers says it has been quacking because it is in their name.
"We have not been ordered to stop using them by any court, so we're happy to quack and it's kind of fun and interactive," said John Scannel, owner of Bay Quackers.
Ride the Ducks did sue another operator over quacking in Philadelphia, but then withdrew the suit.
The owner of Bay Quackers thinks with the economy, this may not be a good time for a lawsuit.
"Everybody on the Wharf is having a challenge finding their customers. This would be a good time, I guess, if you were going to throw lawsuits out," said Scannel.
The next sound you will hear in this case will be from a judge in a courtroom.