Here are a few common errors when using GPS, don’t just turn it on and go – complete some checks first.
Common Errors when using GPS
- Offset Error: A position fixing error can occur when utlising your GPS with older charts. Read your chart and ensure any offset is applied (see ‘Learn Marine Navigation – Why?’ to learn how).
- GPS operates on a spheroid called World Geodetic Spheroid 84 (WGS84). Previously charts were based on various spheroids, e.g., Australian Geodetic Datum 1966 (AGD66): ensure to check your charts to see if it is based on WGS84 or AGD66 and then set your GPS accordingly.
- On your GPS you can select Magnetic or True settings for bearings and courses. Select your preferred settings and remember you only plot True on a charts. (See ‘FAQ What our courses cover’.)
- Are you reading statute miles or nautical miles for distance? Check your GPS is set to nautical miles. (We use nautical miles to match our charts)
- Set your GPS to give you the speed in knots. Knots enables us to calculate Speed, Distance, Time using formula.
- Set your GPS to degrees, minutes and decimals of a minute instead of seconds – to match your charts
- Follow the manufacturer’s instructions when mounting your GPS. Obstructions can affect the signal and the GPS unit can affect the ship’s compass
- Always double check inputted co-ordinates (waypoints). Ask someone else to read and check the numbers too.See what else we offer here (and how we can help you, follow us and our tips!)