Feedback comments after inspection of the (green) Gekos and the (brown) eTrex Summit

Unit	Robin present	Robin loaded	Track stored	Comments on how well/badly the GPS had been performing during the walk
A unit	Yes	Yes	No	Memory not cleared. Good recorded track terminating at Reception Desk. 3 waypoints recorded by leaders: near beginning and at Porters Lodge.
C unit	Yes but an error	Yes	No	The Robin track on the GPS was an incorrect copy! My apologies to the leaders concerned. They nobly had headed out to the conference car park trying to follow the (distant) track and had traversed the West road three times, presumably trying to get a better result. All their movements were accurately recorded by the GPS.
D unit	Yes	Yes	No	Incomplete track recorded by the GPS with one very inaccurate point recorded in SW corner of the walk.
E unit	Yes	Yes	No	Recorded track well-located but the GPS had lost signal badly on SW corner until it got back near college gate.
F unit	Yes	Yes	No	Excellent track recorded by GPS. Showed the South road had been followed on "wrong" pavement. Extra points recorded, apparently in college garden and perhaps in cafeteria.
G unit	No	No & no WP	No	Some very erratic data recorded of first 40% and last 3-4% of the walk. My apologies for the absent track on the GPS.
H unit	Yes	Yes	No	Slightly imperfect recorded data & leaders had traversed the West road 3 times!
J Graham	Yes	Yes	No	The recorded track showed the leaders had crossed roads several times - some slightly off-track points recorded by GPS.
D Puxley	Yes	Yes	No	The GPS had only recorded the last 1/8th of the walked track. Don't know why.

It is clear that there was a problem in the SW corner of the walk. I suspect dense tree cover. Tree leaves are very bad for blocking GPS signals. Also the Google Earth views suggest that both the road and the gardens have a lot of trees.
Elsewhere the results are mostly fair rather than brilliant - OK for normal navigation.
Where good data was recorded it showed the leader's movements very clearly, including points where they crossed the road.
I owe apologies to two of the groups for mistakes I made in the late stages of conference preparation. One Geko had its track missing and one had a dummy track loaded.
I had intended that leaders would store the tracks of their own movements, just to see which keys you had to press. This bit is missing, so I got the tracks direct from the GPS memory.

Unit_C A homage to the heroines who determinedly tried to follow a track which, unknown to them, actually lay way off to the West!

Unit_F Track from another group. It is possibly the best one recorded because the leaders returned along the South road on the side with fewer trees!
The "extra" bit may have been recorded during start-up or possibly by carrying the GPS over lunchtime before switching it off.