GPS - Global Positioning System
Satellite derived position, course and speed
Accurate to 5 - 10 metres.
- Waypoint entry a position or destination where you enter the Lat and Long. The GPS gives you bearing and distance from your present position to the Waypoint
- Routes a series of several Waypoints
- Man Overboard or Mark fix at time of MOB
- Position: - Latitude, Longitude and Time
- Speed Over Ground - SOG (compare with log to get tide effect)
- Course over Ground COG (True or Magnetic)
- Bearing (T or M) to Waypoint
- Distance to Waypoint
- Time to Waypoint
- Cross Track Error (XTE) in Miles how far off the selected track route you are
- Plot Lat and Long on chart maintain log book every hour.
- Back up with another source if possible
- Draw a GPS web on the chart for fast boats
- Find Waypoints from chart, almanac etc. Dont enter the exact
position. Check entry for bearing and distance on chart.
- Use a compass rose as a waypoint for plotting position
- Find Course to Steer GPS cannot do this, you may sail on a
- Aerial Position - should be low, around the stern
rail, not up the mast.
- Aerial failure.
- Battery failure.
- Datum entry WGS84 is usual
- User input on waypoint
- Mobile phones signals.
Click for handout
It has immense benefits but there are drawbacks -
see here http://www.sailtrain.co.uk/gps/limitations.htm
353 GPS Dongle for laptops
28th March 2011
GPS, yacht, XTE, waypoint, wgs84, GPS web, SOG, COG, cross track error, bearing to
waypoint, go to, MOB, nav,