Nav Aids
These mark channels, shoals, obstructions, and warn of dangers
What are buoys?
Two most common forms of chart projections
What are Mercator and Gnomonic?
This U.S. Department initial placed GPS satellites into service
What is the DoD?
The length of a tidal day
What is 24 hours 50 minutes?
The instrument for measuring air pressure
What is a Barometer?
Primary purpose of aids to navigation
What is to assist mariners in determining their position and course, and to warn them of dangers or obstructions to navigation?
This type of chart is often used for planning a great circle track across large bodies of water
What is a Gnomonic chart?
This is a situation in which one person or program successfully masquerades as another by falsifying data and thereby gaining an illegitimate advantage
What is spoofing?
The tidal reference plane used on most nautical charts
What is mean-lower low water?
A steady rise in air pressure is considered an indicator of this type of weather
What is Fair Weather?
The USCG publishes light information for lights in US territorial waters in this nautical publication.
What is the Light List?
These two government agencies are mainly responsible for producing nautical charts
What are NGA and NOAA
The Global Positioning System incorporates what 3 segments
What are Space, User, and Control?
The tidal pattern with one high tide and one low tide during a tidal day.
What is Diurnal?
** DOUBLE JEOPARDY **
The five basic elements of weather that we measure regularly
What are temperature, humidity, air pressure, wind speed/wind direction, cloud formation and types?
This buoyage system is best suited for well defined channels
What is the lateral system
This is a mathematical model of the Earth used to calculate position coordinates, heights, and distances on a chart
What is a datum?
This calculation measures the distance between satellites in orbit and the receivers on earth
What is Triangulation?
The name of a tidal current that flows towards the shore.
What is a Flood Current?
The advisory service which provides ship route recommendations to minimize exposure to foul weather
What is Optimal Track Ship Routing (OTSR) report?
The five types of buoys maintained by the USCG?
What are Lateral, Information/Regulatory, Isolated Danger, Safe Water, and Special Purpose buoys?
A Mercator chart is best used below what latitude due to distortion of land masses near the poles?
What is 70 degrees N?
The use of GPS allows the user to determine _______. _________, and ____________
What are latitude, longitude, and altitude?
A tide formed when the gravitational forces of the Sun and Moon oppose one another.
What is a Neap Tide?
The scale used for measuring/assessing sea state
What is Beaufort Scale?