Fair enough... to me this question shows such a profound failure to understand what GPS speed is measuring that it's scary.
Boating is serious stuff and incompetent boaters are not only a danger to themselves... but to others.
And why don't people use google to ask questions?
"GPS receivers display speed and calculate the speed using algorithms in the Kalman filter. Most receivers compute speed by a combination of movement per unit time and computing the doppler shift in the pseudo range signals from the satellites. The speed is smoothed and not instantaneous speed."
GPS is not a transducer...boat speed is!
Agreed. Google would work. Also it would help sometimes if people would do a search on previous posted Sailnet threads to see if the topic had already be discussed .
GPS speed is not a major safety issue though. I remember 40 years ago when I "graduated" from my days of racing nationally Hobie 16's to my first keel boat how every thing I did was learning. One question led to the next. Despite my racing on Keel boats , owning and maintains one was far different.
There were many patient sailors now that I look back who took some of my inane questions with patience. I understand why now. They were paying it forward as they were in my position once.
There was no internet then to ask and get answered instantaneous questions. There was no sailnet. Damn there were no satellites or GPS them either.
Back to the topic. I use the SOG most of the time for how long to the next Mark. The knotmeter is my bible for trimming the sails and the easiest method for teaching others and my wife how their sail handling affects our speed.
There are many times I don't even put the paddle wheel in.
In the Chessie there is very little current in most of it, so I think we get sedentary about understanding its effect.
Where SanderO sails , it's a big deal. A four knot current can add hours to a long weekend trip if you are fighting it on your return leg. Not even factoring wind and Chop direction. Planning is much more necessary
Chessie sailors for weekend trips really only take wind direction and prediction in their planning.
The more you use it, the better you get at it. Hopefully the less basic questions you ask. However on here you will never have a period when there are no newbies.
As good stewards we need to coax them along with patience till they start answering other newbies questions