Andrew G
Well-Known Member
To those using instruments to check the effect of trimming sails - beware of "moving averages".
Not all instruments (including GPS') give an instantaneously accurate reading. Many give a moving average over several time periods (seconds or minutes depending). Thus they will display a number every couple of seconds but it is unlikely to be as accurate and certainly not as "real-time" as you think. It is highly unlikely to be only in response to your sail trim - it could be responding to the wave that hit the bow a minute or two ago.
I'd check your instrument manufacturer before betting on GPS vs normal instrument. Cheers, Andrew
Not all instruments (including GPS') give an instantaneously accurate reading. Many give a moving average over several time periods (seconds or minutes depending). Thus they will display a number every couple of seconds but it is unlikely to be as accurate and certainly not as "real-time" as you think. It is highly unlikely to be only in response to your sail trim - it could be responding to the wave that hit the bow a minute or two ago.
I'd check your instrument manufacturer before betting on GPS vs normal instrument. Cheers, Andrew