STONYPOINT - As temperatures warm, activity on the Hudson River is increasing dramatically as work on the new Tappan Zee Bridge kicks into full swing and recreational boaters get out and enjoy the sunshine.

With the increased traffic on the water, marine units are stepping up security. Boaters can expect to see slower wake zones, more signage and more officers.

The biggest threat to boater safety this year is the construction barges lining the waters near the bridge. Officials say that the number of barges out in the water has doubled since last year.

Since September, three of the barges have sprung loose. Officials say they're installing 150 GPS devices onto the massive construction units. "When you're operating at night, you've got to take extra caution. Drive slowly and make sure you're aware of your surroundings," says Sgt. John Murphy, of the Rockland County Sheriff’s Office.

Sgt. Murphy adds that boaters should take extra caution at night by going slowly and being aware of their surroundings. He also says to use channel 16 on the radio at all times, which they monitor in case there is trouble.