It includes a programable count down timer, with audible alarm, for starting sequence.

A pretty good review can be found at:

http://www.tramsoft.ch/gps/garmin_foretrex101_en.html

and this also links you to a owners manual in PDF form.

It is "Water resistant up to approx. 3 feet (1 meter) for about 30 minutes (IPX7)"

Terry
N 5.2