Can anyone dive or do you need to be certified?

Certification required, but there are classes (and snorkeling gear) available on-site.

They have classes

Anyone can dive ,with a instructor

Check Groupon for snorkeling classes. There are also some way cooler gems to dive in Florida. Also there is a similar place that you can hike to. I think it's a state park.

In order to enter the den you must be scuba diving or snorkelling. You can dive here as a student as part of your open water check out dives. No certs are needed if you want to snorkel here and equipment is available for rent.

Thanks! That is what I thought from reading about it just wanted to make sure before we decided to make a 6 hour trip down there.