[Tarpon]

Provided the GPS works properly, there is no difference. The accuracy is encoded in the GPS signal.

Two technologies increase the consumer accuracy, WAIS and Differential GPS. I use differential GPS on my boat it's good down to about 3 meters. If you want the most accuracy out of a consumer unit, then get the WAIS enabled receivers -- although WAIS does not work at all times and is more susceptible to outage, it's the best that can be done for most applications. The brand name doesn't matter, although I am partial to Garmin because of the software that works with their receivers.

Surveyors get down to inches by using a form of differential GPS with local transmitters located on surveyed points.

[Delphinium]

Surveyors get down to inches by using a form of differential GPS with local transmitters located on surveyed points.

Thanks I will give that information to him.