How can you calculate the visibility?

How do you adust idle on a Tecumseh 5 hp engine? In Mississippi what is the legal blood alcohol limit if it is determined the operator was Boating Under the Influence of Intoxicants? What rpm range for a 2006 115 HP Mercury? What do 2 short blasts mean on a boat? What type of boat is required to sound 1 prolonged blast every 2 minutes while underway in restricted visiblity? What is the difference between a Boat Number and a Hull ID Number? Where is a water pressure regulator for a mobile home located? You are operating a powerboat at night. You see red green and white lights on another boat. What do these lights tell you approaching from which direction(s)? If grounded aboard a small powerboat which is a method to free yourself? What to do if you see another vessels red and white lights off your starboard? What best describes no wake or idle speed under Virginia boating laws? How do modern submarines differ from past submarines? When a power driven vessel is being overtaken by A power driven vessel which is the stand on Vessel? Why is it important to wear a personal flotation device at all times? According to navigation rules what is the give way vessels responsibility? Can you get married without a license on a cruise ship? How do you remove water pump from 1998 ford windstar 3.0? Narrow flat-bottomed vessels that have traveled over the nile river for centuries? What is the minimum age in Alabama to operate a pwc with boater safety certification? Do boats have basements?