RV SPROUL CRUISE
INSTRUCTIONS FOR THE GPS AND NAVIGATION EXERCISE
The students are divided into 4-5 groups. Each group has a GPS receiver, a copy of the
nautical chart (to be provided), a ruler, and a protractor.
1. Starting at a point just outside Pt. Loma, all groups will take the initial point using
the GPS units at the same time.
2. For fixed intervals of 5 minutes, record the latitude and longitude, speed, and
heading (compass bearing from 0° to 360°) of the ship using the GPS unit. Enter
the values in the data sheet.
3. Take a GPS reading at the sampling location of the sediment cores.
4. On your way back from the sampling location to the harbor, convert the course of
the ship of each 5-minute leg to map distance (map scale 1:100,000), assuming a
straight course during each leg and constant speed.
5. Use rulers and the tic marks of latitude and longitude on the nautical chart to
determine the initial point on the chart as accurately as possible.
6. Use the ruler and projector to plot the course of the ship from the initial point to
the sampling location.
7. Determine the latitude and longitude of the sampling point plotted on the chart as
accurately as possible and compare that with the GPS location. How accurate is
your tracking?
