Wednesday, February 20, 2013

GPS Tracking for Sailors

I haven't yet got round to buying one of those GPS devices for recording my track when sailing. I know some people like them. But I suspect that a track of a typical day's practice would probably look like this track from Owen's Li'll Slice of the Web.


Not sure what exactly I would learn from that.

But don't get me wrong. I know that GPS tracking can be a valuable analytical and teaching tool for sailors. The last few times I have been to Minorca Sailing there has been one afternoon each week when the instructors have given each boat in the fleet a GPS device for the afternoon racing. And then in the evening they have replayed the races on a video screen in a way where you can follow the track of each boat in real time (well, actually speeded up real time) including seeing a display of the instantaneous speed of each boat. This is an excellent way of seeing all sorts of things that affected the race - which side of the course was fastest, who lost the lead by missing a wind shift, how well different boats accelerated out of tacks etc. etc. As Yogi Berra said, "You can observe a lot by watching."

But what use would a GPS be during practice by myself?

I wasn't sure.

Then I came across WallyGPX.

The author of WallyGPX is a cyclist from Baltimore who uses his GPS to track his bicycle rides in order to create what he calls "massive virtual geogylphic imagery." In other words he uses the GPS track like a giant Etch-a-Sketch to draw large scale pictures on the earth.

Here are a few examples of what he does....

Isn't that cool? Check out many more of his drawings and read all about how he does it at WallyGPX.

So I was thinking, how hard would it be to make similar tracks while sailing a Laser on a summer afternoon on the bay?

Well, a bit harder for sure.

First of all, a cyclist can plan his route on a street map first and then follow exactly that route to make his GPS geogylph. A sailor would have to invent some other ways to define his route.

And secondly, of course, all lines directly upwind would have to be zig-zags. So a sailor would have to think of creative ways to include such zig-zag lines in his image. Some steps? A saw? A monster's teeth?

What do you think?

Am I crazy?

Has this winter been too long already?


B.J. Porter said...

Reminds me of Reid Stowe and his Turtle Odyssey.

Noodle said...

Obviously the winter has been way too long, but it sounds like a fun idea; Takes some planning though.
Aside from the zigzag problem, there's the fact, that you cannot lift the pen from the paper - unless you allow yourself to stop the tracker temporarily. If that's allowed, then the zigzag problem is solved too. Just always draw downwind. Anyways, no need to get a tracker. Any modern phone can do the tracking.
Tracking your race is interesting. I bet you miss a few shifts from time to time. That's very visible from the track, - even on a short inshore course.

Tillerman said...

Oh yes. I had forgotten about that.

I don't think I'll be doing a sea turtle with a 5,500 mile circumference in my Laser.

O Docker said...

I'd think the most useful feedback from GPS is measuring VMG on a beat, to see if footing really is quicker to the mark than pointing - or to figure out what compromise between footing and pointing works best in various conditions.

The rules may not allow GPS in a race, but what you learn in practice should help a lot.

Maybe you could try drawing some sausages.

On our cruising boat, the GPS helps a lot to figure out which tack is making better progress to weather in a tidal stream.

meech said...

Is Odocker referring to the Terry Allen song? ...

"She said, she weren't interested in that kind of drawing
But always liked horses, I said "I did too"
But they're hard to draw, she said,?Yes, that was very true?
Said she could do the body okay, but never get the head
Tail or legs, I told her she was drawing sausages, not horses
She said no, they were horses"

Tillerman said...

Half the time I don't understand what the hell the Odocker is talking about, especially when he is talking about sailing... or sausages.

Unknown said...

trackOmeter is a GPS Tracking System with emphasis on EASY. With easy view of all your devices, easy to playback recent events and easy to see alert notifications. trackOmeter reduces the time you spend sorting through pages of reports to get a simple view of past events.

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