baldrick said...
Do GPS Units register 1.3 knots accurately?
Yes.
Why do you ask? What are you trying to measure? GPS are more than accurate enough to measure the difference between just cruising along and sprinting and head wind and tail wind paddling ... which just happens to be 2.4 kph or 1.3 knots.
Domestic GPS are very accurate when measuring speed over a period of time and in an open location. The software is smart enough to ignore momentary jumps in position.
They're not accurate at all for instantaneous measures or positions when you are stationary and reflections and blocked signals from buildings and trees and hills stuff them up very badly. I strongly recommend you do not paddle through trees or buildings.