Steve Kroop at Flytec <<info>>
writes:

Most users of the 6020 and 6030 are aware of the the their ability
to keep track of your last climb and aid you in returning to that thermal with
the direction being shown on the compass rose and the distance shown as the
user-field Dist Therm. Below is an alternative method submitted by Mitch Shipley
that he finds very effective:

I’ve started using the map page of my 6030 to track and re-centering thermals
I’ve lost with great success. The idea stems from some physics “truths” that I
first heard of in one of Dennis Pagen’s books – the source of so many of the
little knowledge factoids I’ve learned about hang gliding. Dennis wrote that a
thermal has a tremendous amount of mass. I’ve forgotten the precise numbers he
used in his calculations, but what I clearly remember was that a thermal was
TONS of mass. Mass moving up as one “chunk” (bubble, column, whatever) and
drifting with the wind. While you can nitpick about how long it takes to
accelerate that mass to the wind speed or what happens as it enters wind
shear/gradient or direction change, the fact is that tons of moving mass
continues to move in the direction it's going and is pretty darn stable for at
least a minute or two.

I’ve been flying with my 6030 on a record interval of two seconds for a while
now. That’s nine hours of flight recording time – which works for most flights,
unless you’re Dustin Martin going 475 miles. After thermaling for a bit, I
switch to the map page and zoom in to where I can see the individual circles and
get enough of them to see the thermal drift/track (about a minute or two of
thermal track). I use the map page this way to get a sense of wind direction and
how it compares to course line. I then use that info to help decide which side
of course line I should go to and how hard I should crab into the wind if it is
cross.

What I began to notice in post flight analysis in Flychart/Google Earth was how
consistent the thermal tracks were. Then I noticed times where I would blunder
off that track and lose the thermal. Sometimes I was stupid enough to think the
thermal “vanished/quit/hit the inversion” when in fact I just blundered off its
course. When I made this error low, I often landed. What I have found and
believe now is that if the thermal is 200ish fpm or better and I have made four
or so solid turns in it, then it is “trackable”. That is, there is enough
mass/size that it continues to go the direction it’s been going and I can have a
decent chance of finding it again.

Now what I do after I get a few turns in a thermal is switch to a zoomed in 6030
map page to help track / re-center thermals. The Flychart/Google Earth track
above is one of those tracks from the recent East Coast Championship comp at
Highland Aerosports. I was going along great at 400ish fpm and then lost focus
(I actually think it was a biological event/necessity that took my focus away at
hour three into the flight, but TMI). Noticing a drop in climb rate and
regaining focus, I took a quick look at the map and navigated my way back to the
core. This technique has worked many, many times. I do this religiously when I’m
low and the cost of losing track of the thermal is high – like landing! Yes,
there are times when you do hit the inversion or drop out the bottom of the
bubble, but more often than not I re-center and/or fly along the thermal track
line and find good lift. The undeniable point is that looking at a zoomed in
6030 map page at high-res recording is very useful information to help figure
out what is going on and make decisions on what to do about it. Try it out for
yourself!

As Mitch mentioned, the record time drops to ~9 hours when the record interval
is set to two seconds. This means that after approximately nine hours of record
time the 6030 will wrap the current recording over the oldest recording. In
other words, anything older than nine hours will be recorded over and lost. This
could be one, two, three, etc. flights ago or the beginning of the current
flight if that flight is longer than nine hours. It should noted that if you use
the above method, the flight memory will be wrapping every ~9 hours which is
five times more frequently than when the 6030 is set to the normal ten second
record interval. If you decide to use Mitch's method, it is recommended that you
routinely clear your flight memory to refresh the section of the memory where
flights are stored (Menu>Clear/initialize memory>Delete all flights).

More on flight recording in an upcoming Tip Of The Week.