Commuters are asked to keep an eye peeled for unusual activity.

In response to Thursday’s terrorist attacks in London, the Department of Homeland Security raised the threat level to orange for mass transit systems, and the U.S. Coast Guard heightened security measures for the Washington State Ferries system.

The Washington State Patrol hopes passengers won”t notice.

“We hope this is a seamless transition for commuters and visitors,” Trooper Kelly Spangler said. “We haven”t done anything new for this.

“Basically, we have a few more troopers assigned and a few more K9s assigned.”

Passengers may see crew members making more rounds on the boat, said Susan Harris, the state ferries” customer information manager.

After 9/11, the State Patrol put extensive security measures in place, she said.

What the department advises passengers now, Spangler said, is to increase their vigilance when traveling on ferries.

“We”re depending on our commuters to be our eyes and asking them to report suspicious activities they see,” she said.

These include anyone taking unusual photographs of, for example, the ventilation system or the diagram of the boat. Or someone who walks away from a backpack or a piece of luggage, with no one to watch it.

A person who is intently watching ferry operations while taking notes or making computer entries would also be considered suspicious.

“The commuters are the key here, not the visitors,” Spangler said. “They ride the ferry regularly and they”re going to notice something unusual.”

Ferry riders who think they”ve spotted something out of the ordinary should either find a crew member or a trooper and describe what they saw.

They shouldn”t be embarrassed to do so, Spangler said.

If people think of something after they”ve left the ferry, they should report it to the U.S. Coast Guard watch line at (206) 217-6232, she said.

“Are people still going to leave their backpack on their chair…or walk off the ferry and forget they drove on? Yes, people are still human,” Spangler said. “We”re just asking people to make some effort to remember their things.”

Crew members who find unattended bags will make announcements to unite them with their owners.

Troopers and explosives-sniffing dogs are conducting random screenings on the car decks of ferries.

Drivers who have weapons, hunting rifles, ammunition or fireworks should tell the trooper about these items when he or she comes to their car to do a screening.

Riders with concealed weapons must have their permits with them and no guns should be buried in the trunk.

“Tell the trooper what you have. That will alleviate a bunch of problems,” Spangler said. “Say what you have, what you”re doing and where you”re going. Communication is really the key.”

Spangler acknowledged that people carrying fireworks will be loathe to admit that, since doing so is illegal.

But, she said, “If you have to tell the trooper you”ve got a bunch of bottle rockets, the liability is much higher if you don”t” and the dog finds them.