SEATTLE -- Of all the problems the Washington State Ferries must deal with, this is one of the strangest.
More and more, people are driving their cars or riding their bikes on ferries.
Then they walk off, leaving their cars and bikes behind.
"It's something that we to deal with more and more frequently based on our ridership increase that we've noticed over the last few years," said Greg Faust, director of marine operations for the ferries.
In the last few years, seven cars and 35 bikes have been left aboard ferries.
"They get on the boat with the people they commute with every day," Faust said. "They walk off with them and forget they have a vehicle."
The problem is that a bike or car left behind may mean a passenger has gone overboard.
"They can literally set off an air search. The Coast Guard will launch their assets. We'll go out and look for this person," said Ian Sterling of Washington State Ferries.
Last Saturday a van was left aboard the Hyak. The State Patrol and the Coast Guard were both called out.
"The total cost on average would be around $10,000 for this type of response.," said Cmdr. Brain Meier of the U.S. Coast Guard.
The driver was found safe. He forgot he had driven on and just walked off.
This busy holiday weekend, the ferry system will have 90,000 passengers. The ferry system is asking the people who drive or bike on, drive or bike off.
"It can delay the vessels and slow everyone else down and we don't want to see that happen on a holiday weekend," Sterling said.