After having a tag stolen earlier in the week I put out another tag yesterday only to have it stop transmitting at 7:24 this morning after an 18 hour track. With the spurious message below (1), a correct message is (2)

$GPGGA,182432,4105.6857,S,17452.7369,E,1,7,1.08,-16.0s ,1ò ?F?àíÅ ,20150116072440
$GPGGA,232351,4105.5721,S,17453.2258,E,1,5,3.07,-3.3,M,19.4,M,,*6D ,4.09V ,Shark2 ,20150115122451

For those interested in what all that means, the bold is information from the GPS satellites, the italics text is added by the tracking tag, the plain text at the end is added when the data is received by the computer on land. Below is a translation of the GPS message

$GPGGA,time,latitude,S,longitude,E,quality of fix,Satellites,HDOP,altitude,m,Geoid,m,,*checksum,tag voltage,tag name,datetime

The yellow track hasn’t been filtered to remove the incorrect GPS positions, so ignore the erroneous ‘spikes’ within the track.

The green circle was the start of the track, the red one the last transmission, the circle is where Nicolas (my neighbour he’s at Plimmerton School) found the non-transmitting tag. I pulled the shark to the surface, and he cut it free from the tag and tether. The square is the Lyon family home.