Question 71Navigation General

The correct answer is B) flashing white light showing a group of two flashes. According to the U.S. Coast Guard regulations, a buoy fitted with a double-sphere topmark indicates that it is a safe water mark. At night, this type of buoy will exhibit a flashing white light in a group of two flashes. The double-sphere topmark is a visual aid that corresponds to the flashing white light pattern, informing mariners that the buoy marks safe, open water. The other answer choices are incorrect because they do not match the light characteristics associated with a safe water mark buoy. A quick-flashing green or red light would indicate a different type of navigational aid, while a flashing red light in a group of three flashes is the characteristic of a port hand mark buoy.