Wednesday, February 17, 2016

FTV Ship's Time

World Time Zones
Hello Everyone! 

A few people have been asking about how we keep time on the ship! The answer to that question is whenever we are going in to a different time zone and we will be getting off the ship we change our clocks to the corresponding time zone. For example when we cross back in to the Eastern Standard Time zone we will be moving our clocks back one hour. However if we are just sailing through a time zone and not stopping we keep our time the same. An example of this was when we were off the coast of PR and Haiti we did not switch our time zones.

When we are in port we always stay on what is called "ship time". This means that even if it is 0800 on land, it will still be 0900 on the ship, and that is the time the ship would use to keep the ship on the correct schedule for watch duty and meal times. Often times to avoid confusion for the cadets on shore leave we switch it to whatever time it is in port. But for most of the time on the Kennedy we do switch to whatever time zone we are in if we are getting off the ship.

Until Next Time,


Watch Real World: Longitude and Time Zones

Keeping the time is crucial to have good results from celestial navigation. Because the Earth is in constant rotation, moving 15° each hour, a four seconds error in the time figure will result in a position error of up to one nautical mile.

Longitude is the coordinate affected by time errors. In fact, if you don't have the correct time, you can't calculate your longitude using celestial navigation. This problem challenged navigators and scientists (even Isaac Newton! ) for centuries.

By the end of the 17th century it was generally accepted that no watch could ever be built that, could perform well enough to be used as a navigation tool. Scientists hoped they could find a way to adjust navigation watches using the Moon position or the eclipses of Jupiter satellites. That was their best bet to help seamen.
Fortunately a man called John Harrison proved they wrong. By designing and building a series of precise timepieces, with innovative mechanical features that corrected the effects of boat movement and temperature variation, Harrison succeeded in creating a new and important navigation device: the marine chronometer.

Understanding Time Zones
Try this time zone quiz
Read a Time Zone Map

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