An alert is out for anyone boating on the Hudson River.

Boaters will not be able to pass under the Tappan Zee Bridge on Friday. The main navigation channel will be closed from 6 a.m. until 4:30 p.m. because of construction on the new span.

Officials say it is one of approximately 70 closures that are anticipated through the end of 2017 as project crews install new sections of structural steel and road deck panels between the towers of the new crossing. Cranes, barges and other construction equipment will occupy parts of the channel during this time.

Officials are advising boaters to avoid the construction site while this work is underway.