"Discovery Cove is a full day adventure with operating hours of 8:00 a.m. - 5:00 p.m. daily. Check-in begins at 7:15 a.m. "
I've arrived around 7:30. By the time the 'gotta be first' line is usually gone in and I've only waited a few minutes to check in. EARLY arrival helps in the summer to ensure an early dolphin time with regard to potential afternoon thunderstorms. That won't be an issue this weekend .....
We've been able to check-in, get lockers & wetsuit/vest and breakfast and be hitting the pools not too much after 8.