Volcano Bay has the same rules as their other parks: soft coolers only. They have a size restriction on their website: 8.5" wide, 6" high, 6" deep, however I have never seen them be strict about this so slightly larger should be ok as long as it's soft. They also prohibit glass and alcohol. We usually bring canned sparkling water (which they check to make sure are not alcoholic), sandwiches, and a small freezer pack in our soft coolers.
I did not see anyone
To be honest im not 100% sure. You do need to walk through security and take all your stuff out of your pockets and take your bag off to walk through the detectors. Hopefully this helped somewhat.
Umm I did not see anyone with coolers but if I think you can take it, the truth is that one spends all the time of attraction. In attraction unless someone stays with taking care of your things. I do not recommend it .
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