he's a digger, which im training up a bit when im bored O.x
If you get alot of digs, you can dig pretty quickly (the wait timer decreases) and even make alot of gil from it.
being at the zone line makes it easier because when one place goes up dry (there is apparently only so many items every 15-20 min i believe), just switch to the next zone and hope that its not dry yet either.
the down side is that you need to train it up and its not agreed upon on what causes the "skill ups"
do some research on the topic and you'll find out~