67. The Helena Gage reads 9.4 feet. The high point on your towboat is 46 feet above water. What is the vertical clearance when you pass under the Helena Highway Bridge?

Vertical clearance is calculated by subtracting the vessel's height above the water (46 feet) from the bridge's clearance above the water at the current river stage (9.4 feet Helena Gage), resulting in 64.2 feet of clearance.