Icy conditions have not stopped repair work critical to keeping commerce moving on the Hudson River.

Members of Marine Diving Service continue repairing hulls and piers when calls come in, even as ice fills parts of the river.

River temperatures are below freezing, but the work remains a priority for crews operating on the water.

Zdenek “Captain Z” Ulman and his team carry out the repairs in challenging conditions.

Ulman said he has worked in water as cold as 28 degrees. He added that crews sometimes work in stages lasting a little more than an hour at a time.

Once submerged, Ulman said the focus shifts away from the cold and onto the job that needs to be done.