Tourists. Just as we seem to find our moorings, their double-decker buses and Topshop bags barrel relentlessly through our lives, leaving gold-dusted angst in their wake. It's lucrative and complicated. But here's something that is decidedly their fault: the Staten Island ferry's weekday on-time performance rate dropped 3 points in FY 2013.

"The No. 1 cause of late ferry trips remains the consistently large number of tourists who attempt to remain aboard the boats to make the return trip, taking significant crew time to clear the vessel, as required by Coast Guard regulations," DOT spokesman Seth Solomonow told the SI Advance.

It didn't used to be this way: from 1999 through 2002 the ferry had a 97% on-time percentage. In 2003 it was 97.8%. Then in 2004 it dipped to 93.4%, and by 2011 it was 90.9%. Now, it's at 88.6%, roughly coinciding with the record 52 million tourists that visited the city last year.

Although announcements alert riders that they must clear the boat at the end of each trip, many apparently fail to hear them, fail to understand them—or they just flat-out ignore them in hopes of staying put.

In response, Solomonow said ferry officials have been adjusting staff schedules to respond to these changes. The tourists are unpredictable, however, he said, with their crowds varying depending on everything from the weather to the economy.

Elusive tourists, like man capri-wearing beads of mercury, slipping from the DOT's grasp and back into the neon ether. Those 52 million tourists generated $55.3 billion in revenue, though the city's goal is $70 billion by 2015, which may be bad news for the ferry. Where do they get the idea to go to Staten Island, anyway?