(Above) A helicopter, doing second unit filming for Transformers 4, flies through the raised Dearborn Street Bridge on August 25, 2013. (Click on image to view larger version.)

October 17, 2014 – For Saturday’s filming from a low-flying helicopter, more than half of the main branch of the Chicago River will be one long “safety zone,” into which entry will be prohibited.

The United States Coast Guard distributed to commercial mariners on Thursday a warning to stay off the river between Lake Shore Drive and Dearborn Street from 7:15 a.m. to 8:45 a.m. on Saturday.

During that time, the five bridges from Columbus Drive west to Dearborn Street will be raised so that a helicopter can fly low between them, filming two boats on the river. The helicopter will make a few passes.

“The safety zone will be enforced in the interest of maritime safety and is in place to protect vessels and persons,” reads a notice from Captain A. B. Cocanour, in charge of Lake Michigan for the Coast Guard.

Cocanour points out in the notice that failure to comply with the order is punishable by a civil penalty of not more than $40,000.

“Moreover, any person who willfully and knowingly operates a vessel in this safety zone without permission from the Coast Guard patrol commander commits a Class D felony and is subject to prosecution in federal court.”

The filming is for Insurgent, the sequel to Divergent, which filmed in Chicago in July 2013 and was released in March 2014.

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