GPS Speed meter

[MI3GTO]

Folks having seen a lot of speedometers that use GPS to measure the speed I was think of getting one. As the GPS can only measure speed over ground (SOG) how does that effect its usefulness? Anyone using only a GPS for speed indication? What about EP calculation? Comments.

[jyasaki]

Depends. Do you have a specific need to know your speed through the water?

Personally, I am much more interested in how fast I'll get someplace, so SOG is what I want.

Not sure what EP is, so no comment.

jky

[EnglishLes]

I think EP is estimated position but if you have a GPS you can use that to give your true position.