I have confirmation on a couple of points, backing up what Brett has said:
1. Playing a par 3 course will get you a high number for the Day at the Beach Award, but will not unlock the award itself.
2. Even though the award states it is for shots from the sand, it only counts bunker shots. So if you attempt this challenge at Kiawah, almost none of your sand shots will count.
So if you want to unlock the award you can do it pretty easily on a regular course using bunkers, but not sandy waste areas, in a red tee CC tournament. I'd suggest Wolf or maybe St A. If you want to shoot a high number for bunker shots, unlock the award first, then go big on Bandon or Bo3.