Definition: A tubular bag that is filled with water in order to add weight to the boat. Bags may be placed at the rear of the boat or along the sides. Increased weight in a boat creates larger wakes behind the boat, allowing wakeboarders to jump higher.
Pronunciation: 'fat 'sak
Also Known As: Phat Sac, Weight System, Wake System, Wake Enhancer
Examples: The wakeboarders wanted a bigger wake behind their boat so they installed Fat Sacks enhance the wake.