As AN reported, it will be quite difficult for New York City Mayor Bill de Blasio to pull off his plan to launch a five-borough ferry system. There are, of course, the obvious issues surrounding subsidies, ridership, operators, and dock placement that could all cause major headaches down the road. While the mayor starts charting his path through these details, another potential problem came to the fore: winter weather.

Specifically, a partially frozen East River. Just weeks after de Blasio announced his five-borough ferry plan, Gothamist reported that the East River Ferry had to discontinue service at least once because boats could not make it through the ice. On its website, New York Waterway, which operates the East River Ferry, explained that the river (technically an estuary) is extremely unpredictable over the winter and that conditions can change within minutes. This, it said, can disrupt the schedule and lead to the temporary closure of certain stops. “We hope that you can understand,” it wrote on its site, “and won’t hate us forever.” It is not you we hate, East River Ferry operator, it is this never-ending winter.

ERF ALERT: Due to ice buildup in the East River, East River Ferry service is completely suspended until further notice.

— East River Ferry (@eastriverferry) February 15, 2015

ERF ALERT: Service is suspended until further notice.

— East River Ferry (@eastriverferry) February 23, 2015