Just a quick question regarding the requirements for garmin tracks:
Would it be acceptable to use a 3sec or 4sec interval for the purpose of recording distance/nm/hour only?
The reason is that the garmin memory only seems to last about 6hrs and that isnt really enough for a long day going for distance. (and longer interval=less trackpoints=more time recorded i assume)

yes, I will be getting a navi soon, however after some interesting issues with my last one i will keep the garmin as backup, and thus would like to know if recording with an increased intervall will be considered acceptable for GPSTC.

Tim,you might run out of battery instead

try logging an alpha run on a 4sec timing... (or just count how many datapoints are in your GT11/31 alphas...)