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April 29, 2002
Vessel Data
Status: Enroute from San Francisco, CA to Papeete, Tahiti
Latitude: 02-55.5’N
Longitude: 135-02.9’W
Distance: 258.3 miles
Total: 3060.3 miles
Gone: 2274.9 miles
To Go: 787.1 miles
Current Speed: 10.8 kts.
Engine Setting: 75 RPM’s 1 engine
Weather
Air Temperature: 91°F
Humidity: 85%
Wind: E 15 knots
Clouds: Cumulus
Sea Temperature: 81°F
Currents:
Water Depth: Fathoms
Sunrise: 0549
Sunset: 1804
Aboard the TSGB
Day 8
Daily Log:
Vessel operations
 For many years, the navigators of the world have used celestial bodies to determine direction and find their position on the earth.
Celestial navigation blend the art of observing the angle of the body with the technical ability to perform complicated mathematical formula
to reduce the observation of the body into a line of position.
Each day at sea, our senior students calculate the error in the compass
by taking an azimuth of the sun. In the evening, they take four or five star sightings with an instrument called a sextant. The sextant
measures the angle of the star above the horizon.
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Cadet Sanchez “shooting” Venus
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When they take the sighting, they record the time with great accuracy. After they work the math
calculations, they are able to plot a line of position on a chart or plotting sheet. Plotting two lines, with a little luck, causes the lines to cross. At
that point a position is determined. The third and fourth lines are added to confirm the position. You can see an example of a star plot done this evening by Cadet Frank Sanchez
Engine Cadets preparing to work in the overheads.
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