Obstructions (Fog)
Report any obstructions restricting visibility to 6 nm or less, including the type of obscuring phenomenon. These phenomena include several types of fog.
At sea, fog conditions describe a reduction in horizontal visibility to 6 nm or less over a vertical depth of 20 feet or greater. If the vertical depth of the phenomenon is less than 20 feet, the term ground fog is used. Mist describes a fog condition that reduces the horizontal visibility to 6 nm or less but not less than 5/8 nm (1 km). One frequent error with low visibility is the difference between fog and mist. If the visibility is below 5/8 nm, it is considered fog. If the visibility is above 5/8 nm, it is considered mist.
Review the observations recorded in the form and answer the question.
Are the weather observations recorded correctly? Choose the best answer.
The correct answer is b).
The weather observations are recorded incorrectly.
What would you do to correct the problem in the encoding? Choose the best answer.
The correct answer is a).
When the visibility is reduced, the present weather column needs to contain the weather phenomena that is reducing the visibility. In this case, since the visibility is below 5/8 of a mile, the weather phenomena is fog (FG).