In the North Sea area, you sight a buoy showing a quick white light with 6 flashes, followed by one long flash at 15 second intervals. Which of the four topmarks shown in illustration D030NG below would be fitted to this buoy?

According to Buys Ballot's law, when an observer in the Northern Hemisphere expe...

How can the accuracy of an azimuth circle be checked?

How are aids to navigation marking the intracoastal waterway (ICW) identified?

When is an air mass termed "warm"?

Aneroid barometers are usually calibrated to indicate atmospheric pressure in wh...

Which term is the angle measured eastward from the vernal equinox along the cele...

Where can the annual change in variation for an area be found?

Which is another name for Universal time (UTI)?

The apparent wind's speed can be zero, but only when two conditions are present....

What should you apply to a fathometer reading to determine the depth of water?