What do the blasts from a ships horn mean?

What color is a marker that indicates safe water on both sides? What is the continent of indus the river? What kind of boats have boat propellers? Where did Magellan sail? Do you have to have a boating license to drive a boat in NC? Why do you need a backfire flame arrestor? What publication must be used to ensure afloat commands have the proper operational type of material handling equipment on board? What is the basic structure of a boat? What is the difference between waves made by the breeze and waves made by a speedboat? What is the history of Eska outboard motors? How full should you fill a fuel tank for a PWC? What was the boat Noah built called? What is a water wheel used for? What is the first thing a boat owner if someone falls overboard? Where can you get a boating accident report? Why does a blimp need to be moored when on ground? What is the weight of 1986 Yamaha 90 hp boat motor? What colour is the navigation light on the port (left) side of a power-driven vessel? how much would 36 inch standard entry door awning in canvas what is the cost? A tall pole that supports the sails of a boat?