1.   Midnight and the start of the working day for the leak detectors.

2.   But he said manufacturers will have no incentive to improve the design of leak detectors unless the Coast Guard requires tankers to use them.

3.   Microwave leak detectors are available, but must be checked periodically by the manufacturer to make sure they are calibrated correctly.

4.   The U.S. Court of Appeals in Washington, D.C., ordered the Coast Guard to issue a rule promptly ordering tankers to install leak detectors.