The in basket: Listen up, readers. This is a really interesting one.

It starts with Ellen Ross-Cardoso, who is curious about an announcement she has been hearing on the Bainbridge Island-Seattle ferry reminding those who boarded on a bicycle to make sure they remember to leave with it. She thinks it’s dumb.

“Are bicycles so frequently left behind on the Bainbridge ferry run that it’s truly necessary to issue a reminder during the already annoying-enough arrival announcement on every run?” she asked.

“In the decades I’ve been riding the ferry, bicyclists were apparently capable until recently of riding off without having to have their memories jogged as to their mode of transportation upon boarding 35 minutes previously. When exactly did their memory issues reach critical mass? Is there a known link between cycling and memory loss? How frequently and in what numbers were/are bikes left behind? Is the announcement making a sufficient difference that it’s worth continuing to subject innocent victims to it?

“And lastly, is it only on Bainbridge? I’ve got a little money riding on the answer to that one.”

“At first I thought it was a joke, but they say it every single time. It’s not funny anymore,” she said.

The out basket: I don’t know why Ellen is so annoyed by the announcement, though I thought it was peculiar too. But I was thinking only of how easy it would be to set a bike aside so it didn’t interfere with off-loading vehicles.

Cars left behind by fares who usually walk on but drove that day and forgot would be more of an obstacle.

But Ellen and I both overlooked a key factor – the uncertainty about what became of the bike rider. Did he or she fall or jump overboard?

The Coast Guard will launch a search if a ferry rider is considered missing after the boat arrives. It didn’t have figures for how often they must respond and at what total cost. But when it happens, they send out what they call a “response boat medium,” which costs $6,631 an hour to operate, says Coast Guard Petty Officer Amanda Norcross. If they add a helicopter (an MH65 Dolphin helicopter, in Coast Guard parlance), that costs $8,600 an hour, she said.

The expense can be avoided, she said, if comparing recordings of the boat being loaded and then being off-loaded show someone biking aboard but walking off.

Which led me to the question that makes this really interesting, in my mind. Are all loadings and off-loadings recorded? And who looks for a match?

I guess I shouldn’t be surprised that the first answer is yes, as the ferries are an attractive terrorist target. And Helmut Steele, the ferries head of security, said it is a Homeland Security measure and there are cameras at all terminals and on each ferry.

“Unfortunately,” he said, “we do have people who, for a variety of reasons, whether it is a challenge or whatever, to jump off a ferry or to swim to shore.” Others do fall overboard or try to commit suicide. “We use those cameras to decide what we have.”

He estimates that someone goes into the water from a ferry and must be sought and retrieved about five times a year. The responses often involve a lot more than the Coast Guard – crews of that ferry and others, police and fire departments with rescue boats.

“My team has the ability to do that within WSF and WSP has a homeland security division,” he said. “They are there in person but also have a monitoring system that has the ability to monitor all these public cameras.” The images go to a control center.

And the bike announcement is played on all ferry runs, not just Bainbridge, he said.

He said the regular ferry rider may not be surprised that one can’t board or leave a ferry without being recorded. There are mentions of it in the terminals, on the boats and online, he said.

But it’ll probably be news to the casual ferry patron – me for example.