Following is what Aquatica's website has to say about bringing food into the park. I'm not saying it's that you can't make your own smart decisions, but I just thought I'd point out what the park officially has to say.
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.
SeaWorld seems less strict about this. According to their website the policy is as follows:
Security Procedures
SeaWorld Orlando security procedures may result in slight delays while entering the park. As a part of this process:
◦All bags, backpacks, and packages are subject to inspection prior to entering the park.
◦As a reminder, the following items are not permitted to be brought into SeaWorld for the safety of our animals and our guests: weapons, glass bottles, cans, any other type of sharp objects, straws, large hard or soft coolers, and any hazardous items or materials.
◦Please leave any unnecessary articles secured within your vehicle to expedite your entry into the park.
◦SeaWorld is not responsible for fire, theft, damage or loss of vehicle including articles left within.