Question 504General Subjects - Assistant Engineer

The correct answer is A. A bridge gage should be used with a depth sounder, which is represented by device A in the illustration GS-0073. The bridge gage is a device used to measure the clearance between the top of the vessel and the underside of a bridge or other overhead obstruction. This is an important safety measure to ensure the vessel can safely pass under without colliding with the overhead structure. The other devices shown, B (compass), C (speedometer), and D (radar), are not directly related to measuring the clearance beneath a bridge and would not be used in conjunction with a bridge gage.