Customer Service is not the ones doing the bag check. There are signs posted at the entrance and the policy listed on the website. I have seen sandwiches not allowed in.
Aquatica is even worse. From the website-
Outside Food Policy
Aquatica has clear limitations on what types of food/beverage purchased outside are allowed to be brought in to the park. Coolers are permitted, but they must be no larger than 16-quart size; large insulated bags are available for purchase at Guest Relations. For guests with special dietary requirements a limited number of unlimited daily picnic size lockers are available for rent at the park. Two picnic areas are located at the bus drop-off area at the front of the park and guests may re-enter these areas as often as they would like during an operating day.
The following food and beverage items are not permitted:
•Picnic lunches or other family portion servings (such as large bags of chips, 2 liter sodas, sandwiches, hot dogs, slices of pizza, subs, fried chicken, etc)
•Alcohol
Coolers may contain:
•Snacks in individual serving sizes (cracker packs, under 3 oz bags of chips, fruit snacks, etc)
•Bottled water
•Baby food in plastic containers
For your safety, the following items are not permitted inside Aquatica: Glass containers, firearms, straight blade knives, large pointed scissors, pocketknives with a blade over two inches, pepper sprays, utensils and flammable liquids.
For the safety of our animals the following items are not permitted inside Aquatica: Plastic straws, balloons, cup lids.