The deadline to purchase excursions before your trip is two weeks prior to departure. Make sure to log on to your Profile and reserve your spot before space sells out! Space is limited and fills up fast.
If space is still available once you get to the resort, you can purchase the extra excursions at the briefing/check-in or at the info desk daily. All excursion purchases on the resort are cash only, and pre-sale prices may no longer be available. Generally the prices go up $5-$10.