The other thing is a question about the track you uploaded. Should I assume it is from your GPS? We use our Garmin GPS during races and it saves many of our previous tracks. I'm wondering if this is where the leg you marked with a "?" came from. There are also moderate wind shifts that occur which would help explain the not so 'erratic' course you show.
Yes it from my Garmin
Leg one was a pretty simple run.
Leg 2 was as close to the wind as I could get.
I tacked to leg 3 under theory that I didn't want to end up down current when I got near shore.
The ?mark at the end of the arrow is the segment of leg 3 where I lost my heading by about 30 degrees and don't know why.
Leg 4 was again as close to the wind as I could make it.
At the end of leg 4, the last 4 minutes you can see how I was again loosing my heading by about 20 degrees again a minor puzzle but the current could explain it except that whey didn't the current bother the course for the first 17 minutes of the leg?
Leg 5 I just motored back to the mooring about 1.3 miles.
Between leg 1 and leg 5 there is an unlabeled leg that was from a prior day.
Caleb thanks for taking an interest in my little puzzle.
I just talked to a sailor who has had many decades experience and he sort of accepted this sort of thing as part of sailing.
I'm trying to be a little more scientific about it.