gps

[xpztqr]

I've never used a GPS and have wondered ...how does one use a GPS to find out a boat's speed?

 

[Pursuit2150]

Re: gps

When the GPS satalites track the antenna, it automatically calculates the speed over ground,SOG.

 

[Spidybot]

Re: gps

Yes, the gps knows your position, updates this and calculates how much you have moved during a certain period by comparing those positions.<br /><br />Waypoints are stored positions. Track-back is leading you back to where you cam from by reversing the points stored on the way out.<br /><br />Some gps's has each and every feature you can think of - based on the same principle.<br /><br />Some can be connected to your PC, shows a map and allows you to plan a trip and when you put in your boat it autopilots your steering to make exactly that planned route.<br /><br />And a lot more. All based on position/time calculations and storings.

 

[blifsey]

Re: gps

I use the most basic, a Garmin GPS12. I'm installed a 12V plug in to connect an adapter to stop using so many batteries. As others state, speed is just displayed on readout like a digital speedometer. I also use unit in car and have timed it between mile markers at 60mph and it was dead on 1 minute. I notice a slight difference between speedometers on 3 vehicles I've used it in.<br /><br />While boating/fishing, I'll mark waypoints for things of interest (fish caught, good cove for swimming, etc.). Then at home, I'll download them waypoints and tracks to the PC (using G7TOWIN) and save. I've got files for most very outing we've had. I name files based on lake and date (e.g. westpoint_20020416). I also combine the waypoints into 1 file for each lake and dump them into GPS before heading out. Using Street Atlas 7, I plot waypoints and tracks to see where we went, etc. Lots of "geeky" fun.<br /><br />BL...