A project to replace a submarine cable that provides electricity for the George P. Coleman Memorial Bridge has closed the main channel under the bridge for boat traffic through Saturday night.

However, the project is not affecting vehicular traffic on the span, said Jennifer Gwaltney, a spokesman for the Virginia Department of Transportation.

Lt. Karen Lee, a spokesman for the Waterways Management Division for the U.S. Coast Guard in Norfolk, said Wednesday that the main channel was closed at 6 a.m. Tuesday and will remain closed until 11:59 p.m. Saturday. She said an emergency plan is in place in case a ship absolutely has to pass through the channel during that time.

Gwaltney said the project is necessary to replace a submarine cable that was damaged by a tugboat in late 2008. The work is finally being conducted, she said, as the matter has been settled with the insurance company for the tugboat.

Lee said that two cables will replace the damaged cable. The span has had elec...